The History of the Jewish Khazars by D. M. Dunlop said that in 448, Priscus is mentioned Akatzir people which vassal of Huns. It is debatable that this Akatzir people is Khazars. In addition, Author says Zacharias Rhetor mentioned about Khazars in 569. Before it was known that Khazars emerged as vassal of Western Göktürk Khaganate in 628. Wikipedia also defend this old argument. D. M. Dunlop claimed that Khazars were in Caucasus before Western Göktürks’ conquering North Caucasus.
My memory mislead me about time of emergence of Tiele People. I am accepting my wrong in this topic.
Uyghurs gained successes against Tang Dynasty more than Göktürks. Göktürks gained sucessess against divided China but when Tang Dynasty is showed up, Göktürks lost battles against Tang Empire and annexed by Tang Empire in 630. In 680, Göktürks won their independence after 50 years subjugation. In 680-744, Göktürks fought against rebellious Turk tribes more than China. In this time period, Göktürks wasn’t more successful than 740-844 Uyghur Khaganate.
I don’t favour Göktürks because of before-mentioned reasons. Politically, Göktürks wasn’t too much successful comparing to Uyghurs and Khazars. As for Cultural influence, importance of Göktürks is far behind comparing to Uyghurs and Khazars.
We are still talking about Roman Empire due to not only their military power but also their influence to World. Therefore, Khazars and Uyghurs are more important than their only political power. Slavs adapted cavalry archer and steppe lancer units from Khazars. In game, Devs didn’t mention this side of Rus due to design and balance reason I think.