Intriguing! I like the part about the Nephilim. ;) I haven’t read much about the Indo-Proto-Europeans, mind you. If the best we can do is conjecture about them because of the lack of direct evidence, certainly there can be multiple interpretations. The downside is that our confidence in the probability of any of the interpretations should be attenuated. I mean, unless the circumstantial case were very strong, we could say the case might be plausible without knowing that it’s particularly probable.
I can see how polytheism—with its view that the king and his family are exclusively divine or especially connected to the gods—could reflect a falling away from or an exoteric misreading of profound spiritual/existential truth (such as of a monistic view of mind’s relation to matter). Then again, we could interpret polytheism as a rationalization of the rise of large cities and kingdoms, in something like a Marxian sense for example, the ideological superstructure reflecting the underlying, material power structures.
Would you say the conventional reconstruction of Indo-Proto-European religion as polytheistic is flawed because of the historical methods? Or is some academic conspiracy afoot? Is the idea that nonduality was the inner, secret meaning of the pantheon, as it might have been for the Greeks (the Mystery cults versus the popular, pantheistic religion)? Do you know of a book that makes your case?