While that video did look a little bogus to me, it is a fact that polo came from an ancient game played by Mongolian horsemen. It was often played after a victory in battle, when the defeated leader's head was used as the ball. Lacking that, they had to settle for a dead calf or someother animal.

Perhaps there was cross fertilization, as both the West and the Chinese adapted it independently after being invaded by the Golden Horde, to which the video referred.