I believe the Hakka are mixed blood descendents of these folks, The Curse Of The Red-Headed Mummy.
There are records of their migration all the way across China and the Hakka with curly hair or high nose-bridge were killed during this/these migrations. They are related to the 'red-headed' folks via than Han, Xiongnu, Miao, Yuezhi and ultimately the Schythians, all Indo-Asian steppe people.
Very interesting read. The theory is that 5700 or so years ago, groups in Southern-Germany/Austria/Chechia learned to ride horses, and were able to quickly expand their range in all directions, including the British Isles (Celts) to the west, Scandinavia to the north, and the -stans and beyond to the east. All very politically incorrect and throwing accepted Chinese history for a loop.