Well, the numbers aren't exactly with the aliens, given that there are seven students this time around, plus the Hall Monitor, Peer Counselor, and my other new addition of Lab Geek. So yes, the Brood Alien does give them a bit of an edge, but it seems like the Lab Geek, plus the number of students, should keep things even.
It was because of The Faculty movie that I added the Brood Alien in the first place -- the film has the alien leader disguised as a student, spying on the others as they try to fight off the aliens, and that leader could take over people. Since it was so similar to the Alpha from the werewolf version, it seemed natural to try it out here. :)