Those could work too.
Now that you mention it, I thought that some characters could have better PLs in the game.
Like:
Kenshin and Archinine. In his history, he was known as the 'Tiger of Kai.' Archinie is a strong, looking, dog lion-tiger animal. I feel like it would suite him quite well.
Masamune should have a dragon, or it could be one of it's PFs (I like Braviary a lot, but I have a reason). His nicknamed was the 'One-Eyed Dragon. Also, he quite a temper, like a dragon. I couldn't pick a dragon type specifically, yet.
Keiji should have more of a carefree Pokemon, due to his personality. Maybe Quiqsire?
Well, overall, I think they choose great Pokemon.