Theory about David, slight spoiler
Before you read on be advised that this contains some spoilers.
I feel that Ash from Alien could actually be David. Or be a droid that David corrupts. We don't know what happens from the end of Covenant to the actions of the original movie, but it's a theory I wouldn't rule out. Ash admires the creature, (maybe like a father). when I say Ash could be David, his mind could have been uploaded to a newer droid, and maybe he has too to protect his identity and his true intentions.
