I can't picture Hinata as Hyuga leader the way she is now either. She's still too Naruto-obsessed. A part of me is hoping Hinata gets a reality check when she gets out of IT, but I doubt it since she looks so sad on the movie poster. I see her moping over Naruto because he's with Sakura and already the image is cringeworthy.
Who knows. Maybe she does mature in The Last and is somehow a great Hyuga leader. I guess that would be the magic of a timeskip.