sogdia

Your challenge is to have Sogdia be considerably more successful than it was IOTL.

After Sogdia was conquered by the Muslims, numerous Sogdian refugees came to the Uyghur Khaganate. There, they converted the Uyghur nobility to Manichaeism, and Manichaeism became the Khaganate's state religion. What if the Uyghurs had stayed Manichaean?