Just to derail for a second:
About the whole Vasquez killing an Alien = Wolf holding back two Aliens bit, I rewatched Aliens yesterday and decided to time how long it takes for Vasquez to kill the bugger, and how long Wolf holds back the Aliens.
Vasquez: From the Alien falling down on top of her, to her kicking its writhing body off of her after her leg's been burned, is exactly 8 seconds.
Wolf: Holds the Aliens there for 9 seconds.
"Oh big whoop!" you say, "One second difference! Get over it!"
Except in the 8 seconds Vasquez encountered the Alien, she only stopped shooting it long enough to kick its head into the roof of the vent. As soon as it was on her she was shooting it in the stomach, chest, and head; by the time she pinned its head, it had already sustained damage there. All in 8 seconds.
And what happens when Wolf grabs the Aliens? Nothing. He just stands there, and they flail like retards. Vasquez killed an Alien in the time it took for Wolf to finally track on to the damned things.