Basically Tibet is divided into three provinces, Ngari, Tsang, and Ü. Tashilhunpo is the monestary that serves as the seat of the Panchen Lama and administrative centre of Tsang. The thing about Tibet is that there is also a north-south division, between the south which has a denser population and the north which is populated by scattered bands of herders. I believe that the way it worked was that the herders were subjected in a loose way to the government which was based in settlements in southern Tibet. All of the maps I've seen of Tibet continue the three-fold division into the northern part, which sort of implies that the nomadic area was split between the the three jurisdictions, yes. I don't really have any hard evidence.I’m a little confused, so was that central-northern area under Tasihlunpho’s jurisdiction?
They weren't in the map that was shared and I didn't make any changes other than Tsang, I might do some more edits to the map later, of which those would be part.(Also is Powo, Sagya, and the Bhutanese exclaves being missing indicative of something I don’t know about their status or is that just like, to make Ü-Tsang lies complicated for clarity’s sake on the areas under Lhasa?)
I think it just might be a normal division of the region based on an administrative decision, since this region has always been sparesely inhabited, by groups who only remain in a certain location at one point in the year, or cut through land that has no one living there all the time. I think we should ask Admiral Kolchak.
Also I think the vassal region was under Tibet, not Tashilhunpo, but thank you for correcting the disputed borders mistake