For the european balance of power of that period, I wouldn't doubt that the difficulty of the game is set too hard, for the second AI problem you mentioned I suppose it was just like the history, think of the time last of a 30 year war for example.
I found the selection of these 3D models of commanders to be anoying, and the ctrl selection of troops also unberrable, if you take the game as a lesure activity it certainly is not. But the system of the game is among the best and the most clear ones! If their really isn't any patch I must would pissed^
