Yes, the strat map AI is fairly good. It's just the siege bug that also makes some non-sieging armies behave strangely too. Also, I'd say the brigands were a bad thing, they should've been replaced by larger armies more coming seldom. I agree that better battles will change the strat level, but as long as you can retrain troops in newly conquered cities it's way too easy. I've been thinking about ways of making retraining impossible and I think I know how to achieve it so if EB doesn't change it, I'll mod it myself after installing EB. Anyway, the strategical level BUGS are the main problem, because even if AI would be powered up in some ways it would behave strangely as long as they're there.

Here's how to win a campaign against any AI: if it's safe, go conquer an enemy city. If it's not safe, stay in a settlement and keep making money and training better troops. If you are besieged, reload before ending turn. When you have a strong enough army, attack the enemy army that's just standing outside your settlement. When you're strong enough, go for a new enemy settlement. In the beginning of the game cities are so small that they can be held after conquest, so you needn't worry about revolts until later, and by then you've grown so strong you don't have to worry about revolts either, because you have stronger armies than the opponent.

I agree though that improved battles will change many things. The limit of max 20 units means that strategy is no longer as important as in real life, which means the game will, after a certain point, almost favour tactics over strategy. I see no better solution to that than the method CA has implemented, as it would result in battles with too heavy hardware requirements - somewhere there HAS to be a limit. So perhaps, after some thinking, I'll take back part of my statement and simply say that the bugs are the only problem at the strategical level, once battle speed issues etc. have been fixed. The battle speed is after all one of the main reasons why cavalry is so powerful in R:TW, because their speed and ability to hit isolated units and rout them quickly is what makes them so important - otherwise they'd have to use more hit and run tactics, and take casualties each time when withdrawing.