To me Ty looks the best because he could have a really cool moveset with rangs and his other moves, plus I personally think we need more cartoonish animal characters in the game. Also Ty is a born fighter, anyone remember this commercial from 2002?
My Mains: Sly Cooper & Sackboy
My Subs: Ratchet & Clank, Sir Daniel, & Parappa
Abe Croc and Ty were my guys growing up although I don't think croc really deserves a spot if i'm honest and Abe should only get in if they can figure out a decent moveset. His whole gimmick is that he's a weak pathetic slave. Not a fighter. Sure he can possess people and transform into a god but that only takes up 2 supers and he has nothing else going for him in terms of fighting. Ty would be awesome though he's still sorta relevent and is about to have something of a resurgence over the next few years so I genuinly expect that he'll make it into the sequel.
So Croc would be a good fighter but is no longer relevent enough.
Abe is relevent enough but wouldn't make a good fighter.
Ty would have awesome gameplay but is just slightly too obscure for now. That's going to change pretty soon though.