I like this, as in my headcannon, the original jocky and engineers were two separate things. The engineers were trying to emulate them. My main issue with the engineers being retconned into humans as a backstory just didn't do nearly enough to appease my imagination. That's the problem with 'origin' films. They can easily fall short of our expectations. Keeping in mind that Dan Obannon was the original author, and he saw the alien as cosmic horror. Ridley Scott was the director, who I think watched too much 'Ancient Aliens' in recent years.
Anyhow, I'm glad you drew, literally, a distinction between Engineer and Jocky, as it fits my headcannon. I do wonder if all of the true Jockey would have had the same body layout as the original we saw in A1, or if that particular one's design was specific to it being fixed to the ship, while others may have had legs, or some other physical means of locomotion.
