The enemy campaign AI in Total War games is famously inconsistent, with a tendency to cheat or behave bizarrely in the presence of an non-AI character.
Remember, not all these work well together – so if you’re going to install multiple mods, use something like the All-in-one pack, the Zen pack or the Radious Collection. We’ve gone through those available and picked a selection of the better-maintained and better-designed ones. Finding Shogun 2 mods is always going to be a pain until the Steam Workshop comes to Total War – especially as good ones seem as rare as a tasteful Horo.
While we wait for the next Total War game it’s worth considering upgrading Shogun II.