This would come as a surprise (nay, shock) to Hinduism’s clerical classes and it’s millions of followers in the sub-continent.
You write: “Hinduism doesn’t even HAVE a basic dogma or rules. What you’ve specified can all be removed and hinduism would be unchanged.”
If by this you mean that just about anyone can claim to be a Hindu including those who do and do not believe in gods incarnated as monkeys, baboons and reptiles, and who believe that an immersion in the Ganges can be regarded as an attempt at toxic suicide, then we have a belief system that is as evanescent and shifting as the desert winds and sands.