At least that appears to explain the different behaviors seen in the game.

The reason for Expert-only is that I was a miniatures/board wargame player for years before starting with computer games, so many common concepts were already learned when I began playing M-TW. At first, I focused almost exclusively on the battlefield, playing many, many, historical and custom battles - soon graduating to Expert difficulty. But I'd never played a campaign until after discovering the two main forums dedicated to this game (this one and the .com), and I wondered about all the discussion and enthusiasm for the strategic aspects of the game. So I tried my first campaign on Hard, found the battles not challenging, and restarted at Expert - and I've been hooked ever since!

The computer's A.I. is far from what an experienced human opponent could offer, but is so much better that what's been available in the past. There's just no comparison! But I can readily see why, once you feel you've fully explored the single-player game, that multi-player offers an almost addictive step up in challenge. Too bad it's tactical battlefield play only - the thought of a multi-player campaign almost boggles the mind!