—Nomadic is (usually) ‘code’ for Caucasian.—
I don’t know about that - in my experience, the Chinese media tends to be pretty unambiguous when it comes to Caucasian/foreign racial identifications in archaeological findings.
Ref:
http://news.xinhuanet.com/english/2006-12/25/content_5529959.htm
http://english.peopledaily.com.cn/200606/28/eng20060628_278224.html
http://news.xinhuanet.com/english/2004-07/06/content_1576929.htm
Anyway, aside from the Sai, Yuezhi and perhaps the Wusun, most nomadic groups in northern China are not known to be Caucasian e.g. Nuzhen, Qidan, Donghu, Sumo Mohe, Heishui Mohe, etc.