"Buddhist" monks are depicted in the opening scene. Buddhist monks were almost certainly present in even the Western-most regions of the Silk Road in the 9th-10th centuries. In particular, one Sufi saint-Shaqiq al-Balkhi (d. c. 810 CE)-talks about meeting "shaven-headed mendicants" on the Silk Road that seem to have been Buddhist. To be clear, those folks are *not* Himalayan, and the robes are not what Himalayan Buddhist monastics wear. I say this as a professor of Himalayan Buddhism. Regardless, in my opinion this an excellent approximation of the silk road circa 800 CE.
The 70th episode of Vikings.