Hacker: Legion because hackorz skills are da best
Leader of team b: Garrus because Miranda tried to be taking over trout completely. Fall back, son.
Biotic shield against swarm: Samara but Jack would have been fine too really. I just like Samara more as a character.
Guard the Normandy: Tali, Grunt, and that merc dude (forgot his name). I know the Tali thing is random but I had no idea where to put her since I didn't choose her for the hacker but probably should have sinde Legion is a stronger fighter than her. She totally died when I first tried it, so I corrected that by placing her as a hacker the second go around and then Legion took her place.