wether its the children or the adults, the engineer/jockey in alien is still significantly bigger, i mean significantly. when i say signifcantly, i mean like comparing the size of a 17inch macbook pro screen, to a 37 inch hdtv screen. the way its being talked about here is like ' a few feet' as if its the difference between a 13 inch laptop and a 17 inch one. i really don't think so. which ever way we cut it, it doesnt work, suited jockey or not. the jockey in the trailers still looks pudgey and small compared to the fully framed jockey in alien.
lets just also be clear on something, when everyone watched ALIEN and saw the jockey, there was absolutely no impression of a humanoid that suits up, there wasnt any impression like that at all, it looked almost like skeletal remains. can anyone come here and say they guessed or suspected a suit even? i mean before we ever heard of prometheus.
now, if we had an xeno included in Prometheus, and it happened to pop off its penile looking head and underneath it turned out to a humanoid inside, would you feel the same way about the original xeno? would it still seem like an alien? of course not.
Giger knew what he was doing, thats why they hired him.