The same alphas that let Ultron speak for five minutes?
Most people have never met most people they don't immediately fight. Would you not think, Star-lord as a human at least in looks intrigue the Avengers, not to mention a tree and a racoon looking species. Would you not think he would say before any fighting began that he was human?
The whole point of Civil War was hero infighting and the accords gave them a reason. Iron Man vs Thor kind of made sense in Tony saw Thor taking away his prisoner, Thor is a hothead. The other fights were then Hulk mind control.
Of course they could give them a valid reason to fight, but frankly if it's them fighting each other because they've just met, then that is beyond simple screenwriting.
Not to mention it wouldn't even be that fun as pretty much any version of the Avengers would have to be nerfed as to not trash the Guardians. Thor, Hulk, Vision and SW would all pretty much win the battle individually.