@cacra
I'm curious, what kind of historical are you looking for with combat? Total War style? HOI style? Surely not CIV style. From the beginning, EU has been dice-roll combat, line-up unit vs unit with modifiers for as long as I recall.
There are so many ways to define ahistorical. Breaking a unit, having them retreat one province then get killed by the fresh victors was even worse. Every combat engagement was just a stack wipe that required a few extra clicks to finish. If I recall, the shattered retreat move was meant to bring the combat back into balance between attackers and defenders.
Sure you then had your whole country as a combat zone, since it changed combat to "blanket the enemy to bring back the stack wipe strat." So the latest expansion reworked the fort system to restrict movement, which (supposedly) cuts down on the "win one battle, loser gets wiped, aggressor always wins" war game. It's an improvement, actually
less ahistorical from a certain point of view (whoever loses the first battle always lost the war? VERY ahistorical), but I would never call EU combat "historical". It's still line-em-up, roll the dice, count the losses until someone breaks and runs. (edit - Oh, and try to get the other side to attack into a mountain province.)
I'm just curious which aspect of history you are looking for. Not that I can help you (I'm just a fellow poster here), but seriously I don't have the framework needed to understand what you mean when you say you want historical and fun.