Opinion: God does miracles, Angels use technology, and there are Bad Angels and good Angels. The little greys are bio mechanisms which demons may inhabit, to do the bidding of bad Angels working for satanic deception. They are connected to a greater dimensional realm via their mental state but without a spirit. The vehicles are real technology built by fallen bad Angels. The Good Angels also use technology and may have their own UAPs. The vehicles of Angels are inter-dimensional.
Interesting theory 🤔