King Arthur and King Arthur II are, unfortunately, pretty dumbed down. AI is pretty bad, if not terrible, and it's quite easy.
I've finished both of them, and Magic is really 70% of the battles. 20% is ranged and 10% is tactics. 3 heroes, 6 stacks of archers, 2 scout cavs, 2 heavy cav, and regulmar infantry to hold and pown the mob, and you'll stick with that till the end...
Fallen Enchantress : Legendary Heroes, was a great find. Combining a bit of Civilisation, with RPG elements, and pretty well. There's a nice modding community, and all the heroes and regular units that you "design" can be used by the AI later. Play with a challenging AI at least though.
Can be frustrating when Wildlands and monsters destroy your outposts/cities, while the AI have dozens of monsters roaming in their lands, but only get their troops, sometimes, attacked. Pretty fun game.