Firstly, i like the idea of David responsible for creating xenomorph. For me that twist worked perfectly ( i just couldn't expect something like that) and i just like his character in generall. But i also like idea of xenomorph as bioweapon of some ancient race. So, i tried in my mind to somehow connect these two excepting each other points of view. Please, read to the end or you can miss the whole point!
I see Engineers as very ancient race. I think that there was fraction of Engineer scientists whom invented Black goo. Goo was in first place used to create life on other planets (as seen in beginning of Prometheus). Scientists got a lot of respect for that invention. They try to perfect goo and eventually figure out how to create xenomorph. Obviously, outbreak happened, many civil Engineers were killed and for that scientists fraction was cursed and forced to go away from their homeworld. Technology development stoped and civil Engineers had to create and use the same technology for few thousands years (it explains why Planet 4 Engineers had so outdated technology). All information about what happened and xenomorph recipe were destroyed. In that time scientists came together barely having any technology apart from ships that were given to them. But they didn't give up and tried and tried to rediscover xenomorph recipe.They created their own society disconected from own species and that make them so cold and unmoral. Eventually they ended up on LV-223 and almost suceed in their goal (you know what happened next with them). They planned to test their Black goo on Earth. They didn't hate humans but saw them as apropriate test subjects for their experiments. Why last Engineer was so outraged when he was woke up by Prometheus crew though? He reacted as scientist would react to lab rat asking for more cheese and warmer cages.
As was written before civil Engineers tried hard to wipe out everything related to xenomorph. But something left. Some hints, some clues. Maybe they turned into some kind of legends that Engineers told to their kids. And David found remains of such legends. But he didn't find blueprints. Very important point of my thoughts is that David got inspiration but not step-by-step tutorial (despite the fact that it existed before).
So, at least from his point of view he really created but not recreated his Perfect organism.
And i really would love to see scene in possible Covenant sequel where David will finally faces Engineers with his army of fleshy Xenos but they will use their own biomechanical Xenos against fleshy ones. I would love to see that universal upset on David's face in that moment when he will realise that in the end of the day he actually didn't create anything
Maybe it's not very accurate but... what do you think about