Now, I've been studying ALIENS in pretty much hyper-molecular detail and I've realised something about Crowe and Wierzbowski.
It always bothered me, in the interviews or literature, somoene says something like "Even the characters who die early you get a sense of who they are and the loss of them". I dare say someone can pick out the exact quote from somewhere.
But Crowe and Wierzbowski, that's not true.
You have to look carefully to see them. Wierzbowski has no dialogue (other than possibly a scream at the last). Crowe I think has one line (off screen at that).
Then I discovered: they're stunt guys. They're not really characters, just there to flesh out the numbers of marines, and do some stunt work. I'm amazed that Crowe even got that one line.
Wierzbowski's lack of dialogue may even have allowed the production to pay him less (this is a UK thing).
And lastly, having identified Wierzbowski, I noticed a goof. When Apone says "Wierzbowski! Come on 'ski, on your feet", said character is on the left side of the screen, on his feet, and getting something out of his locker!