Why do the Robots want the Engine Back/What or Who are the Robots? (Spoilers Duh)

You've been warned about spoilers.

Season 2 of Lost In Space shows that the Robots live on a few worlds with a ring around the planet with strange ruins corresponding to said Robot(s). They seem to just lie dormant for the most part, constantly being recharged by lightening.

(Time for a Recap) For some reason one day one of their ships crashes on Earth and causes a natural disaster scenario. Scientists then use the Drive/Engine to construct a lifeboat for the human race. During this particular voyage, a group of Robots attempt to retrieve the Engine that belongs to them... The ship is attacked by the Robots the main ship is evacuated to a nearby planet. Will Robinson helps one of the Robots and it forms a bond. (Recap Done)

But why do the Robots want the Engine Back? Surely they have more than that one in particular right? Other than it being an obvious way of faster than light travel, what more does it mean to them? Again, if they lay dormant on the planets doing nothing, why would they care so much? Is it just a plot point of "it's ours we want it back!", "It's the only one" or could it be more than just an Engine of sorts? A part of something greater? A piece of a much more larger puzzle into their way of living?

I'm beginning to wonder if maybe the Robots are just a vessel for their builders. Perhaps, millions of years ago, faced with an extinction level event the builders built the Robots to continue living by perhaps uploading their consciousness into the Robots, some form of virtual simulation. Over time just forgetting their mortal selves until there was nothing but what they have become now?

Or maybe I'm just over thinking it and they are just evil Robots. But the question is still, what value to them is this Engine? Are they the protectors of it for some other species? Why did a Robot go rogue and just so happen to be near Earth and crashed into it unless it was suppose to? Unless that's what it's always done? Could the Engine allow for time travel?

Will's Robot... What if instead of the Robot having A.I. and learning from Will, the Robot is remembering feelings it's experienced before it met Will? The face of the Robot seems to house more than just lights, there's something in the lights, what if it's actual Neural Activity?

Ben Adler sacrifices himself to save the Robot called Scarecrow. What happened during the lightening strike when Adler was touching Scarecrow, did their minds merge? Was it Scarecrow that helped save the Colonists/Kid's Ship, or was it Adler in the Robot? We've sort of learned that Will and the Robot share thoughts sometimes even visions. Maybe Adler and Scarecrow do now as well? The lightening for sure roasted Adler's body. I also believe the revival of Scarecrow may of uploaded it's memories of Will Robinson to the rest of the Robots in that area of the ring.


Anyway enough of my rambling. Thoughts? Hit me with it, I can take it.