Do you mean the Jedi and Sith, or the Republic and Empire? None of those are canonically primarily human. It's just that we usually see human characters in the stories for reasons of ease of costuming and/or relatability for the audience.So the races would be more like Rodians, Twileks, Ithorians, Devorians, Duros, Wookies, etc. -- basically there would be hardly any inner-race conflict because the real battles are between the good faction and the bad faction which are both primarily human.