Those frame grabs illustrate something I mentioned earlier in the thread -- that I guess it was intended for the Xenomorphs to appear enormous (although the ones in the mine certainly weren't). We're seeing 'em out those windshields hundreds of feet down the road ahead, which makes 'em the size of double-decker busses, or bigger.

I never liked the word "linemen" to describe Frank and George. Always makes me think first of football!