Ancient people were horrible everywhere. It's not really an argument for anything.
These aren't "ancient Tibetans"... this is quite literally the Tibetian government directly prior to the Chinese takeover, ie. within current people's lifetime. There are direct, credible witnesses to what Tibet under the current Dalai Lama's government was like. The current Dalai Lama was picked by people who tortured their citizens and gouged out their eyes for trying to organize away from serfdom. The current Dalai Lama oversaw a feudal system where these sorts of punishments continued to be carried out.
Tashi Tsering's autobiography details the extensive whippings and sexual assault he experienced working in the current Dalai Lama's dance troupe, prior to the Chinese takeover.
This is not "ancient" history.
Tibet was much more closer to SA (rigidly authoritarian, brutal punishments) than Pakistan (democratic election of leaders, less chopping off of people's limbs)