When going for the UHV, I harassed China and went for Mathematics to get Confucianism, which gave me catapults. I used warriors and catapults (promoted with first strike) to fend off the barbarians elephants until I could get spearmen and elephants of my own out, and eventually settle the rest of the subcontinent.
I also placed a couple of warriors on hills to fogbust most of the subcontinent but I noticed that the barbs still appear even in visible territory, so I'm not sure how effective that is.