I will follow your new mod with great interest! I'd just like to draw your attention on an important point about your reconstruction of Afghanistan in this period: Zunbils don't exist. Paradox ingenuously added them in TOG and Charlie, reporting to now quite outdated works, but Zunbils are an historiographical myth.
In several Muslim sources, we find the title رتبیل rutbil. Since omissions or additions of one or two dots are current in manuscripts written in arabic script, Marquart suggested to emendate this form into زنبیل zunbil, assuming this was a theophoric title built upon the name of the god Zun, attested in the region by some Arabic sources, and maybe by Xuanzang. This solution implied though to emendate every muslim sources, including Tabari, Baladhuri and the Tarikh-i Sistan, which all have rutbil, and to leave aside the fact that no Chinese sources give us a form close to zunbil, but it was widely accepted by scholars.
It has been totally abandoned, however, since the discovery in the 90's of the so called "Bactrian Documents", which confirmed the hypothesis Alessio Bombaci already made in 1970, that is that rutbil correspond to the turkic title eltäbir, a title given by the Türks to lesser nomadic (and sometimes non-nomadic) leaders who were not from the imperial clan Ashinas, but who were allowed to keep their authority upon political groups they used to rule. Indeed, we read in this documents the title eltäbir in its Bactrian form hilitber, and according to Nicholas Sims-Williams ("Ancient Afghanistan and its invaders: Linguistic evidence from Bactrian documents and inscriptions", in N. Sims-Williams [ed.], Indo-Iranian Languages and Peoples, 2002), it is this word who give the form rutbil, with a metathesis of l and r.
The so called Zunbils are in fact Turks who bear the title eltäbir. According to Inaba Minoru ("The Identity of Turkish Rulers of Hinudkush from the 7th to the 9th centuries AD", Zinbun, 38, 2005), they are from the same stock that of the Turkshahi of Kabulistan, since it is a conflict surronding succession in Kabul who made a scion of the Turkshahi fled southward and established himself in Zabulistan as Eltäbir/Rutbil in 680. Using Chinese and Indian sources along Arabic and Persian ones, Inaba makes the consistent hypothesis that both Turkshahi and Rutbil were Turkic Khalach/Khalaj.
I hope you'll find this informations interesting, and you'll mod this region of the world accordingly!
