I think you worry too much about what mods to apply to make the game more demanding when you have not even played it yet.
Trust me - Dominions is not an easy game and you will certainly loose the first few games. It is true that there are certain combos which the AI can't handle very well, but until you find those (which might take quite some time) there is no need to mod anything.
By the way, once you get good enough with Dominions, you might whish to play with other humans instead of AI only, which is actually much more fun.
I hereby order you to download the demo!
