He definitely kept the original in mind when he made the other, to make sure there was a lot of contrast.
Naruto's cover is bright and colorful and from the ground up. Heavy on blues, greens and red/orange in a natural landscape.
Samurai 8 is blue only, with shades of black and white, and the bit of yellow/peach for the hair and skin and the spot of red for text. And he's in an otherworldly, half robotic/half ocean plants landscape.
There is nothing at all in the Samurai 8 cover that would remind you of Naruto. Like if you didn't know did Samurai8 and picked it up randomly. So yeah, they went out of their way to make sure it was different.
edit: - The second cover almost feels like what a Minato cover might have looked like, you know?
I do see that with the Minato cover. It also reminds us with Samurai 8 how it's way different due to being more of a sci-fi series than anything else with how Hachimaru looks on the cover with the coloring going on.