Ok. I'm starting to buy into this two alien species theory here. SJ's and Engineers. One big thing is convincing me of this.The flying "saucer" ship seen over the waterfall seems like a distinctly different technology than that of the "derelict" ship on Acheron. Thus, TWO species.The "saucer" is something we have not seen before in the "Alien" universe.
100% Agreed, two species and then whatever the monster/vulture in the myth is. It seems like they might place the "gods" as the owners of that saucer-looking craft, and the Titan race as the space Jockey; however, I could easily see it being the other way around. The gods atop mount Olympus are depicted as very human, have character flaws, full personalities etc. So these could actually be the tall, bald guy(s). Also matches the Nephillim, Annunaki, and in a way the legends about the tall, pale Atlanteans.
Prometheus/the Jockey Race, being Titans, can still be the Elder gods that are later replaced by the Olympian gods, often described brutally, but in metaphor. These are decidedly less human characters when you really look at it. For example Gaia, the idea of the Earth Goddess, is a Titan. The greek myths talk about one of the Titans, I think Kronos, being castrated by Zeus as part of their cosmology (idea of how the cosmos/earth came into being) and takes place above the Earth. Later on Prometheus is practically seen as a servant to the "gods" who reign alongside Zeus.
So the "gods" replace some of the Titans as rulers over the Earth in a sense. This may be key, because it has lots to do with Prometheus going against the wishes of the gods and giving humanity the flame like in the story that we all should know by now. What most probably don't know is that Kronos was devouring his children because he knew one of them would eventually overthrow him. This is why I believe the idea that the Space Jockey became a slave race of the gods is true. Gaia hides the child in a cave deep in the bowels of the Earth/herself, where Kronos can't see. And eventually that child comes back and castrates him, reigning monsters down across the land in the process as his dripping blood/semen falls in the ocean, creating islands .Much later there is a war between the Titans and the gods, and Prometheus lives with the current round of humanity on the Earth. Then his whole story starts, where he helps the humans by giving them the flame.
I think the gods' punished the Jockey/Titans by taking them off-Earth with them in the distant past; stranding them on distant rocks, and making them a slave species, test subjects, fused creatures, and hosts for their genetic experiments i.e. the vultures. I think the gods are actually represented by that human-like child(Zeus) that grew to castrate and enslave its maker (The Jockey/Kronos) raining down and creating the first wave of the Greek monsters into the ocean.
There's a chance the tall, bald guy is originally from Earth in the Ancient Past, but they came to rule over those that made them. And that the Jockey may still be a creature inside the suit.