‘Richard’ is obsessed on the AIT/OIT question. I think that if you look at the short history of India in WHEE you will in fact see the simplicity of the overall structure. The question of India in the Axial Age is vital to understanding, yet never discussed, and Buddhism is filtered out of the discussion, usually, when the subject is Hinduism.
I think that ‘Hinduism’ (mostly a modern/western invention really) is wrapper than can be unwrapped to leave Indian religion visible for the first time.
I can help it if the Aryan myth in India has gone on so long, and yet is false. My history of India is actually a breath of fresh air in that regard.