M is D, I envy you your predicament. My biggest worry about the game system is that I lose so few.

I myself have a ghastly suspicion that auto-resolving battles probably gives a more "realistic" result, whatever "realistic" means in the context of a TW game.

Part of the fun of the game system is learning the best way to handle any particular unit on a battlefield. And one of the nice things about the campaign game is that you don't start out with very many types of units, so learning how the inter-relate (or don't) won't be all that complicated.

I've never worried much about what the game characterizes as the extent of my victories. I care much more about what the consequences of that victory are in terms of my overall campaign. I'm usually much more concerned with making sure that the enemy army disbands at the end of the battle, or that one or more of my units got some battle experience, than with the adjective the battle attaches to my win. For all I know this aspect of the game (heroic vs. non-heroic nomenclature) is totally bugged, and I couldn't care less. The little crossed swords on the map are fun to look at, but I'm usually more interested in knowing that I deflected that horde of Huns that was bent on sacking Constantinople, and they're now headed for the Dalmatian coast.

Maybe if you described one of your battles you could compare notes on how other people would have fought it. Your basic question is pretty vast and reads a bit like an invitation to re-write Sun Tsu.