This is a universe where economic prosperity for a country is determined by a sequence of mercenary contracts written by civilians or political entities that entail escorts, protection, assassination, and even full-fledged wars. It's expected that you would maintain and improve your relative strength on your own time time to increase your effectiveness as a shinobi. Aside from a scarce few exceptions like early Part 1 Kakashi who admitted that he had not encountered anyone notable that could challenge him for some time, the characters are always improving their strength, intelligence, speed, jutsu arsenal, chakra manipulation, or refining their fighting style.
This is an assumption with no basis on canonical facts. We don't know if there is a mandatory resting period after a mission that hampers time for training or if you need to 'reserver' time for training fields. Another question is how you are even able to train specific areas like your fighting style or learning new jutsu when you are alone? We haven't seen a 'jutsu library' where you can find jutsu to learn and, in Naruto's case, fighting against Kage Bunshin doesn't refine his fighting style as it is extremely hard to impossible to find mistakes in your own fighting style.
Besides, the amount of time between the different arcs is too short to truly train anyway. My estimation is that the whole of part 2 took no more than three to four months with the most down time being between the second and third 'sasuke recue' missions.
I did read the Part 2 fights. Sage training and bijuu training largely focus on harnessing the external forces of substances or beings to supplement Naruto's already existent abilities, true, but that doesn't mean any improvements in statistical areas while in these forms wouldn't yield any benefits for his basic skillset as well. His chakra manipulation has undoubtedly improved as a result of the allocation and creation methods of those modes- some proponents even argue that it's superior to Sakura's when he distributed and manipulated it to coincide with the Alliance shinobis' respective chakra style.
How would balancing the intake of natural energy improve on anything? It doesn't. All Naruto had to do was exactly that (which was hard, no questions). After balancing the intake of natural energy he had to 'hold it'. When he used jutsu after that he had the same amount of control as before.
And some people say that distributing Kuramas chakra was impressive? It was anything but that! There isn't any need for true control as all he had to do was distribute it evenly throughout the Alliance, there is no need to consider different chakrastyles as Kurama's chakra formed a shell around the shinobi, controling it was no problem as (to me, so that point is really debatable) the shell conforms to the users will.
Naruto was already fatigued due to his prior usage of Sage Mode which consumed an ample amount of his chakra. He was going into that fight with only a third of his usual stamina available because of the battery clone system he utilised to refill himself with sage chakra. The fact that he could persist in holding his own in taijutsu with the same being that was giving Kakashi difficulties is a testament to his incredible endurance and CQC aptitude - and yes, it's a far more notable feat than anything Sakura has ever managed to scrounge up when punching Part 1 Ino in the face several times before getting knocked out.
You can't take Kakashi's fight against Tendo Pain as argument as they never engaged in a taijutsu battle and Tendo could play to his strengths. This is especially important as neither of the paths specialised in taijutsu but Pain was a character completely build on the Rinnegan's abilities. So it's actually nothing special when Naruto can hold his own in a taijutsu battle with Tendo Pain.
And while we don't have an equivalent to the pain fight for Sakura you shouldn't forget her fight against Sasoris puppet army, which, by his admission, destroyed/conquered an entire country.
As you referenced previously, the 3rd Databook is only applicable up until the end of the Itachi Pursuit arc. Don't mince words by arguing that Base Naruto never improved again just because he happened to have access to superior modes. The confrontation with God Realm still stands, as does his incredible performance against Sasuke in the initial stages of their second fight where his colliding attacks with Sasuke were generating shockwaves from the impact alone.
As i stated above, Naruto's taijutsu fight with Tendo Pain isn't so much a compliment to Naruto but rather to Nagato's own taijutsu. In fact, i personally would say that Naruto's showing was pathetic! He specialises in close ranged combat, engaging the enemy with clones or himself in taijutsu and finishing him off with a rasengan either through tricking or brute force, but couldn't defeat an enemy that was the most ninjutsu specialised paths of all!
And his fight against Sasuke (you mean the truly last one?) doesn't count as both had the activated powers of their reincarnations, so they're not 'base mode' anymore.
If you want a more direct comparison then you need only look at Naruto and Sakura's respective performances against Omoi and Karui. The former was capable of holding his own in a 2 against 1 scuffle, whereas the latter was promptly dispatched with a simple jump kick because she was either inattentive of her surroundings or she was incapable of avoiding due to the linearity of her fighting style prohibiting her from adjusting her posture in mid-attack.
Erm, no? Look up the chapter, Naruto barely managed to achieve a short stalement. And Sakura recieving Karui's attack was more of a testament to Karui and Omoi's teamwork than the ability of either Naruto or Sakura. And if you analyse the positions of Naruto, his clone holding Karui's sword, Karui and Omoi you'll see that Naruto was severly disadvantaged against them. Karui and Omoi had the upper hand from beginning to end.
Would you like to know what Sakura's method of fighting is classified as? It's a boxing style called "The Slugger". Here is the relevant information concerning it...
"The slugger (also brawler) often stands for everything that's brutal in the sport. A lot of sluggers tend to lack finesse in the ring, but make up for it in raw power, often able to knock almost any opponent out with a single punch. Most sluggers lack mobility in the ring and may have difficulty pursuing fighters who are fast on their feet. They usually throw harder, slower punches than swarmers or boxers and tend to ignore combination punching. Sluggers often will throw predictable punching patterns (single punches with obvious leads) that often leaves them open for counterpunching."
Sound familiar? Just sprinkle some basic-level regeneration on top and you have Sakura.
This can actually be applied to Naruto, too. He just uses clones to mitigate problems. Oh and again you forget Sakura's superior reflexes (i very much doubt that Naruto could evade a hail of senbon like during the first stage of the Sasori fight) so counterpunching isn't that much of a problem.
All of which I give Sakura credit for after making the necessary deductions that account for her needing Chiyo to lead her through the first half of the fight so she could acquire this information. Ironically, the moment Sasori shifted attack patterns to something that she was unfamiliar with, Sakura folded under the pressure and required Chiyo's intervention again. This shortcoming when confronted by something that requires her to think on her feet has been ongoing and noted several times in the Kage Summit and war arcs.
No, the moment Sasori used non-area-affect iron sand attacks Sakura was able to stand her ground with minimal help which became 'no help' in matters of three or four manga panels.
Recall the fight: First, senbon hails. Sakura only needed help with the stinger. Second, iron sand bullets and 'iron shard rain'. Too fast to react or dodge if you're not familiar with iron sand. Third, geometrical iron sand structures. Sakura accurately read the attacks and countered them. Fourth, iron sand web. Undodgeable but Sakura mangaged to sustain only very few injuries. Fifth and Sixth, fire and water attacks. Seventh, puppet army. Sakura displays an extremely good showing against a jutsu that conquered a whole nation, especially when you consider that she was on her last legs.
You also overlooked Naruto's various stints of creativity that have taken Jonin by surprise when he was a 12 year old Genin. What about his comprehension of God Realm's cool-down time after using Shinra Tensei, Kaguya's dimensional transfer, or exploiting Kiba's heightened sense of smell on more than just one occasion. All of which outweigh reading some finger movements through prolonged analysis of a puppeteer whom she was mostly helpless against except for like 30-40% of the fight. This is the same girl who was successfully tricked by Ino of all people and believed that rushing a virtual god with unspeakable powers was an apt strategy. She's just fortunate that Madara chose to impale her through the stomach with a chakra rod instead of vapourising her with one of his many techniques.
The information about the Shinra Tensei was from Kakashi and transfered through Katsuyu, Kiba's heightened sense of smell was (or should be) a no-brainer as he was from a notable clan in Konoha and Naruto was a class mate. The only one i give you is the Kaguya one.
So summa summarum i would say that Naruto had definetly the edge in 'ingenuity' but not by much, especially considering that 'ingenuity' is base Naruto's only true strength. And considering that Sakura wasn't helpless for more than maybe ONE phase out of eight, i would say that her showing wasn't too much worse than Naruto's which is actually a compliment as Naruto is the main character.
Regarding Madara and her rushing him. That was the correct choice of her, as the distance between them was so small that Madara had no time to do much else than stab her and use his 'shadows'. And, again, this fight can't be taken as argument for or against base power levels as noone was on his 'base level', the only ones to have even a chance at doing anything were our 'poster boys' thanks to their god given powers and Madara would have won anyways if Kaguya wouldn't have been revived. This fight, together with the one against Kaguya, were the worst ones in the whole manga as there wasn't anything looking remotely like strategy, tactics or ninja behavior.
I'm sorry, when was this? Sakura's genjutsu affinity is one of the most underutilised qualities in the manga. Her feats in that area are virtually nil. The only two times where Naruto failed to deduct that he was in a genjutsu with Sakura nearby was in early Part 1 when his genjutsu stats were literally on par with Lee's - hardly a noteworthy feat in hindsight, especially with how scarce genjutsu usage is. The latter was intentionally written by Kishi as a vehicle for showcasing Sakura's strength. It was her thoughts and what she learned that was in the limelight at the time, not Naruto's.
During the first fight against the zombie clone of Itachi during the 'rescue Gaara' arc. Everyone on his team was suddenly 'defeated' but Naruto didn't even think about it and istead rushed Itachi. To detect that this was a genjutsu it needed something obvious as Itachi dispersing in a cloud of crows and reemerging. In comparison, Sakura immediately detected that they were on the second floor rather then the third one during the chuunin exams through something as simple as knowing how much stairs they went up.
Analysis and evasion have been the obverse of Sakura and Tsunade's fighting styles since the fight with Sasori. Their medical techniques permit them a certain amount of leeway that causes their fluidity and grace to wane, not that they had much to begin with. With the Byakugou, their strategy consists of tanking any attack that the opponent unleashes and then responding in kind with an attack of their own after being impaled on a stick. When she's forced to act on a spur of the moment, Sakura can't even react to some wooden spikes that Hinata was repelling. She's easily prone to deer in the headlights syndrome when confronted by something that she didn't account for.
The only medical shinobi who has kept true to the doctrine of survival through avoidance all of this time is Kabuto.
Neither Tsunade nor Sakura can rely on the Byakugou Fuin as it has to be periodically recharged. Oh and did you actually see the (admittedly very short) scene of Sakura destroying Sasori's puppets? You know the scene practically copied in 'The Last'. You can't call this 'not gracefull' without calling everyone else's fighting style ungraceful. All scenes of Sakura and Tsunade tanking damage were actually instances where evading was actually counterproductive (as it consumes more stamina/chakra) or the wrong choice as tanking would allow them go close to the enemy.
And please show me what you mean with 'having problems reacting to wooden spikes that Hinata was repelling'. I can't recall any scene in the manga where this happens!
Only after Zetsu neglected to consider that he was referring to a pig, not a human, which Sakura picked up on and referenced again to confirm her suspicions. She wouldn't have assumed a thing if the circumstances behind her profession didn't entail the study and care of various different species and their anatomy
Yes, but she did because that was her job. And additionally she didn't visibly react to such a blunder which Naruto would have (because he seriously lacks emotional control).
That they did - but unlike Sakura, we actually have direct evidence to corroborate the idea of Naruto's base speed improving. It's interesting that you neglected to acknowledge Naruto keeping up with Sharinnegan Sasuke and having a brief exchange with him before resorting to Kurama. That should have immediately resolved any claims of Naruto's Base speed stagnating after the Itachi Pursuit arc.
Again, that's not base-level as both had their 'gifts'. I don't even know if they kept them after they lost their arms but considering Sasuke still has has the Rinnegan i would argue that the moment they recieved their gifts from the Rikudou Sennin they ceased to even have base-levels.
You may call me narrow-minded but i refuse to acknowledge their new status as their basic one. Neither of the two worked to attain that power, it was given to them because they were reincarnations of some half-aliens and now it courses through them 24/7.
Is this the same Sakura who was incapable of reacting to falling down a pit of lava or against some wooden spikes that the fodder were managing to dodge? Her nondescript genjutsu resistance - which Naruto happens to possess as well, being a jinchuuriki in sync with his bijuu - is moot because neither one uses illusions. Her briefly shown analytic skills against Sasori don't apply to opponents where she is not given the necessary time to carefully examine their abilities. Sakura can observe all she wants for however many seconds she has before being blitzed by Naruto, it won't make a difference.
Oh, and what could Sakura have done to prevent her from falling into the lava? She was practically teleported directly above the lava with no chance to do anything! And that includes Kakshi! And again, i have seen no instance that she had problems dodging wooden spikes. Naruto's genjutsu resistance stems from Kurama, meaning it's non-basic Naruto. And only because we didn't see them using genjutsu doesn't negate the fact that Sakura has higher stats and is thus objectively better than Naruto at it.
And since Naruto isn't that much faster than Sakura she won't be blitzed as i've argumented above.
How does Sakura have more combat experience? She's only ever fought a handful of times in the manga. Naruto has been challenging Chunin and Jonin tier opponents when he was 12 years old. He's challenged two of the Sannin to battle on at least one occasion, and trained for several years with the third (one of those Sannin being the superior of Sakura even at the end of the manga). The entire 4th world war was won thanks primarily to Naruto's actions. He fought in every major theatre against multiple Kage level opponents before challenging all of the bijuu, the Jinchuuriki, including the Jubi, various Akatsuki members, and ultimately the original user of chakra herself.
Compare this to the battles that Sakura has under her belt... Some disposable Sound genin, Team Oboro's mirage clones (off-screen), Ino, Sasori (her only impressive battle), a White Zetsu spy, Jubi fodder that everyone was taking on, a half-assed distraction run against Juubi Madara, and a single punch from an advantageous position above Kaguya (it's an impressive feat, true, but it's hardly comparable to what Naruto and Sasuke did at this time who were handling like 80-90% of the legwork with Kakashi and Obito taking another 9-19% of it).
How you came to the conclusion that Sakura has seen and done more in combat than Naruto is beyond me.
Simply because she has more missions than Naruto. She has 8 C-rank, 4 B-rank and 1 A-rank missions more than Naruto. And Naruto had only two notable fights which i would say count towards battle experience: Pain and Kakuzu, one of which was primarily fought with his power-ups (sage-mode and Kurama). And every fight after that was nothing more than DBZ-esque slugfests that, again, were fought with power-ups.
If you actually look at all the notable fights (which discounts fights like those with Deidara and Itachi), you'll see that Naruto had only one notable fight without powerups. And that was against Kakuzu.
Ah, and you can cross out 'training with a Sannin' since Sakura had that too...