Love it ;) Dark Nebula
As far as the Set Reports we have to remember they may not be experts on all things Alien and get stuff mixed up a bit, they will just say it how they saw it...
And so the 5 stages could be designs, these could be props they created that wont be used, they could be in the movie as previous versions that David created that he evolved.
Some set reports said they saw the Deacon, this clearly had the Goblin Shark Influence and so i think this is a trait the Neomorphs may carry over... but the person who said the Deacon returns, they also said they cant wait for it and mentioned Jurassic Park Raptor
Now the Deacon does not have a Tail....
However Fire and Stone Comics toyed with Deacons with Tails, so maybe it develops a Tail or similar organisms related to it either from the Goo or as a procreation method of the Deacon produced Deacons with Tails as far as what Fire and Stone was working on before they just had Xenos instead.
So maybe indeed a Deacon could be the basis for the starting point of the experiments?
I doubt the Deacon from Prometheus makes it to the ship, but Fassbender said "as far as we know" when asked about if David and Shaw arrive at Paradise alone... I however think this would be a big FLAW as the movie showed David and Shaw left before the Deacon was birthed and Concept work showed the Deacon had left the Lifeboat just to witness David and Shaw on their way as the Juggernaught leaves the Moon.
So the "as far as they know" could mean Engineer in Cryo, or maybe Worms who knows... A Deacon would pose a threat to David and Shaw so that makes a bit of a Plot Hole.
So if we see Deacons in this movie even if only as previous experiments then David would have to RE-CREATE the Experiments...
Which would need a bit of intervention if it was merely Nano-worms that needed Holloway as a means to pass them onto Shaw like a Sexually Transmitted Disease if so then DAVID could Re-infect Shaw
Or David would need a Humanoid Male for Sperm... maybe Engineer or related or indeed, a Male and Female...
So its a lot of interesting options...
As the SMOKING GUN... is Davids experiments would needed Hosts as you cant Perfect or Evolve something if you have no means to see previous attempts full Life-Cycle.
And.... There are Human or Humanoid Baby/Fetus Skulls in his Lab/Work shop and these dont grow on trees.
