How to rule Otomo provinces as Mori?

I started conquering Otomo during turn 50+something and finished at during turn 78. Conquering was not difficult but ruling is, extremely.

The first province I captured from them was Nagato. After more than 10 turns, there is still no sign of improvement in the happiness of the population there. As a result, I had to exempt it from and earned nothing from them. Similar problem occurs to the other provinces. The main reason seems to be Christianity (my clan's religion is Buddhism of course). To make the matter worse, I had to maintain sizable armies in those provinces besides exempting them from tax. All in all, I was losing a lot of money from those Otomo provinces.

What did I do wrong e.g. attacking them too late?

shogun-2-total-war

Best Answer

On top of raveturned's answer, often it's easier to just allow a rebellion. It's easy to get stuck in the mindset of keeping order at any cost, but that's a mistake.

When you leave a province unhappy, the first turn it will experience negative growth from rioting. The second turn, an army will spawn. Kill that army, and you'll get a sizable military crackdown bonus that will cancel out the unhappiness from religion/conquest for a while. Now you don't have to keep a garrison and can tax them as normal; when they forget about what happened to the previous rebels, you'll either have converted enough or you can do another crackdown.

Hell, sometimes it's worth intentionally provoking provinces in peacetime for some free rebel-slaying experience for your generals.