Christians arrived in eastern China during the Tang dynasty. The Jesuits went to China nearly a millennium later. Did the Chinese notice the similarities?
Perhaps the intervening centuries of upheaval leading to information loss. Or perhaps the denominational differences--Ricci being Catholic, Alopen being Nestorian--were large enough for the Chinese to treat them as different.
Or not?
Followup: What relationship, if any, did the Chinese perceive between each of these groups and Manichaeans?