BTW, that was just this last Tuesday evening when I saw the Hakka version of the "three emperors" for the first time.
They used to herd reindeers too!
I've studied some about the Hakka and Xiongnu. They made five migrations all the way across China. The ones with Caucasian features were singled out and killed along the way during these migrations.
It is my opinion that the Xiongnu and the Hakka are related to the Caucasian mummies found in the China desert a few years back. The Curse Of The Red-Headed Mummy