At the start of the game, I saw an oppurtunity to build a large wall between my base and the Bavarians'. Turned out to be mostly useless, since when Peace Time ran out, I had a full formation of Harquebusiers supported with cannon outside the wall, plus a decent force of 100 Mounted Chausseurs and two squadrons(40 each) of Dragoons ready to reinforce if necessary(it wasn't) and many Musketeers(who not once participated in the entire game).
Their main army was smashed by the Harquebusiers and cannons. Unfortunately, my guys were beat up too, leaving the cannons out of the rest of the game, and my Harquebusiers to wander around taking isolated mines. The next step was to send in the cavalry to take down pockets of troops trying to rebuild their army as the Dragoons approached their town.
We set up just outside, using the Dragoons to snipe outlying enemies. For some stupid reason, they kept charging them with Mortars without any backup. I just let them do that, capturing a bunch to rain destruction on their buildings. The death knell came when about 150 Mounted Chausseurs galloped right to the crowded center of town and began slaughtering everyone there. Everything after that was mop-up.
Cossacks: European Wars: Back to War. First time beating the AI on Very Hard in a land battle.