Mabey you could have it where the humans are a broken bunch of "serious" marines with absolutly no teamwork, even though everyone tries to do it.
"Working together definatly was not part of the training program! Much less how to work a teleporter, they just told us to kill those alien freaks on this ship. Luckily thats why Jimmy was for. Even if he is missing a kidney, 3 fingers, and his second liver for being the guinney pig. What? Only one liver? Obviously you are not a scientist, as your information has absolutly no logical fact or reasoning behind your statment. I on the otherhand took a serious study corse on the physiology of a human, and before you ask, I cannot show you my degree. And according to my logical reasoning, we definatly have 3 livers... i think. You only need one of them anyways, hes got two left."
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Human team ScientistDefinatly long-winded, but mabey thats the point

As for the Aliens, they could be a semi-naturally talanted fighters, who know to work as a team. Thier objectives are obvious, yet their motives are not. The catch? They work and think like a bunch of frat boys in a state university.
"I put the prostitution in institution baby!"
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Really cheese and clech'e catch phrase