I think the big issue is a theological one: if a Neanderthal is created, does it have an immortal soul?
Don’t know.
The mechanics, IMHO, are irrelevant. For example, no one thinks IVF babies don’t have immortal souls, and the mechanics there are the same (by a dramatically lesser degree of complexity, of course).
The Jewish answer is, of course they have a “soul” — an immortal part -— all Creation has an immortal part.
The question is sticker if: (1) that soul is made in the image of G-d and (2) does that soul lack awareness of good and evil -— i.e., is this a “pre-Fall” creation.
That is what I never got. If they do clone people and animals, pretty much anything, does God give it a soul? That would make a good movie. A bunch of soul-less demons walking around, but you can’t tell the difference. Freaky huh?