Another popular one is 'Lands to Conquer'
I just started playing with mods for the same too easy reaon, am at about turn 30-40 as milan using LTC on vh/vh and I'm starting to lose finallly! Strategic and battlefield ai is improved, battlefield doesn't seem vastly better but it is a bit, strategic ai seems a lot better, vicious even.

I know there's a separate version of LTC with just the battlefield and strategic ai changes, I'm not sure if I like all the other changes with the mod I'll probably try that next. The author is Lusted who works for CA now, hopefully that bodes well for empire