After reading some where and sparking my memory, I remembered that NS teams are set up as
1 = Frontiersmen
2 = Khara
3 = Frontiersmen
4 = Khara
That makes 4 teams. Now just imagine this:
2 Marine teams vs 2 Alien teams, each side working together.
4 Way free for all, every team trying to gain victory.
Marines and Aliens vs Marines and Aliens
Wish I had the coding capacity to make it happen.