In one of my recent games, I managed to block off quite a bit of land which kept Shaka and Qin fighting for what they could get. Shaka was Hindu, Qin founded Judaism and adopted it after a while (not immediately) and I also went Hindu. It didn't take very long for Shaka to rather expectedly declare war on Qin, but he didn't have much success the first couple of thousand years with them signing peace treaties every now and then only to break them once they had expired, but eventually Qin bit the dust and capitulated.
Considering I had been left to my own devices and the other two had been fighting more or less all the time, I was miles ahead in tech and had started to prepare my own military force, because obviously Shaka was going to go after me next. Religious buddies at Pleased means jack to him! With a smile, I could see him rallying his forces in his border city - horse archers, maces, catapults and such. Unluckily for him, I was massing rifles and cannons, so when he declared (he had a couple of knights by then, but otherwise mostly backwards garbage) and had taken one step into my culture, he had his complete stack wiped immediately and there was nothing left in his cities. A couple of longbows, some crossbows and the occasional short-lived knight that tried to run by, so I took a city or two every couple of turns. Qin sent a stack of like two trebs, two knights and a mace, but once Shaka was down to two cities, he broke free and they both capitulated. And of course Qin had overtaken Shaka in score by then
After capping them both I shipped my forces over to Toku and Izzi (of course...) who were Buddhist friends, but Toku gave up surprisingly quickly after losing his army and one city. Izzi gave up after losing her cities 2-4 (Madrid would have been next up).