Would it be possible to stop the AI from suiciding stacks on Acheron? I think Acheron is an interesting feature, but it also makes the game significantly easier, as the AIs seem to give capturing the city high value.
For example in one game the Luchuirp attacked Acheron's city with a 15 unit stack of catapults, golems and Barnaxxus. The end result was most of the units dying without taking the city. At the time that stack was probably the most powerful military force in the game.
This was happening with the 2.3 version of the mod. I've since then upgraded to 2.41, and I play with Acheron off, so can't say if it would still happen.