Well, the theme of the manga/anime is that they get strong while protecting those who are precious to them (my prrrrrecious *ahem*). Hence shika would be stronger fighting alongside chouji and having them protecting eachother, however i'll be disapointed if chouji makes it... Not because i don't like him, but because ending his story here will leave him with honor, and the whole butterfly thing, final suicide attack, and someone has to die damnit...