Why on earth is there no real fighting

[Kommodus]

Kommodus - I think one reason decisive battles stand out in history may be because they were rather rare. I suspect it was more common for losses not to be wildly different between 2 sides.

I'm sure this is probably right. However, would it really be desirable to include these indecisive clashes in the game, as they would have little effect on the outcome? While some battles will of course turn out that way, they don't generally add much to the gaming experience. You might as well just assume that such skirmishes are going on all the time in the background, but that they simply don't warrant the player's attention. I would say stick to the exciting stuff and leave the tedium out.

I think part of your solution (2) - better strategic AI - would be the AI evading battle more and sticking to more STW/MTW epic confrontations. At present, the AI seems able to retreat from battle once but then is caught. This seems a gamey aspect of the turn-based IGO-UGO set up.

This is a good point. The AI should be able to avoid battle unless cornered.

I also think introducing some genuine campaign attrition - due to disease, desertion etc - would be warranted. RTW even reduced this - no attrition for besiegers

This might add realism and challenge, but I think the irritation level that would result would outweight the potential benefits. I'd rather not have my units slowly shrinking until I'm left with a bunch of depleted units when I haven't even fought a battle, and be forced to go back and retrain them (a task I find tedious and boring). Once again, this goes back to the "focus on the exciting stuff and leave the tedium to the auto-management" principle.

It would also be good to make it harder to replace losses - something like WesWs homelands concepts (one house rule I like that simulates this is not to recruit core troops in cities with a culture penalty).

Yes, this is a good concept worth implementing, especially since it would make things harder on the player in the late-game, when you are fighting far from home. If you want to recruit troops away from home, you simply have to rely on the indigenous ways of fighting, like Hannibal did - it takes a long time to change a culture.

Would all this be less fun for the player? Well, I must confess I fought 150+ battles in my Julii campaign and they were usually unbalanced battles I would have won anyway.

It saddens me to hear this. I wish this were the type of game in which you'd fight maybe 1/5 that number of battles in a typical campaign, but each one would be an interesting, exciting clash in which the AI usually outnumbered you and almost always had a shot at winning. I hope that future games in this genre move in that direction.

I guess the way I would like to see campaigns happen is this. You spend a number of turns preparing for war with your neighbor, while he prepares as well. When war breaks out, each power has a large army (maybe two or three at most). The armies clash, and the winning side is able to occupy several cities while the losing side holds on as best it can while it raises another army. Once this is complete, another big battle takes place, in which the previous loser either turns the tide or loses even more lands. Thus, a large empire might be defeated in three or four battles, while a small nation might be crushed after only one defeat.

Small, lopsided skirmishes add nothing to this game. They should have been minimized from the beginning. But then, all this is just my opinion.