Quote Originally Posted by Alexios
Perhaps I'll just skip over "Hard" and go directly to "Expert" and play an MTW game on that setting to see how challenging it is.
If you want the most intelligent A.I., hard is sufficient by my knowledge. It also increases the combat stats of A.I. units with 10-15%: not so much you'd notice, but enough to give it an edge when equal units are fighting. On expert the A.I. gets a bonus of 30% as well +5 morale. The latter is important as it makes A.I. last far longer than yours. I do not know what the differences are on the campaignmap.

Quote Originally Posted by Alexios
So would you say the AI engine in RTW is superior to that in STW and MTW?
Actually, I would say it's inferior to S:TW and M:TW. There has been a lot of debate about this in the Coloseum, and some people argue that the R:TW A.I. is the same as that of M:TW, but is handicapped by the increased battle speed and decreased balance. This may be true, as slowing down and balancing the game does improve its performance; but M:TW A.I. would never frontally charge a unit with a weaker unit whereas R:TW A.I. does. In M:TW the computer would scout for hidden units whereas R:TW forgets about them even if had seen them take up ambushing positions. M:TW A.I. could do ambushes itself, but I never seen R:TW pull one of on the battlefield. The M:TW A.I. clung to hills when defending and would relocate if you managed to get higher than them. In R:TW you can just walk around them to get the higher ground and it would never try to stop you.

R:TW is somewhat more flexible with formations, but its general performance in battles is nowhere near that of S:TW or M:TW. BI and the latest patched did improve things, but it still not at the same level (though I haven't tried BI yet). All in all, the A.I. is a lot worse in battle. It can be improved through modding, though.