I always thought there were a variety of 'theisms' in Hinduism, such as polytheism, monotheism, henotheism, pantheism, panentheism, etc.
There are. Hinduism has all the varieties of theism, even atheism.
But polytheism apparently represents a majority of Hindus in India. But considering how vast Hinduism is (and how difficult it is to accurately define), I don't think it's a very large majority, especially taken with all the Hindus of the world.