If you move about 6 or so infantry brigades along the left border of the map you can push the union troops off the hill while staying in cover for the most part and either box them in by the river and destroy them or box them in in the top right of the map and destroy them and also if the cav units slip by pop skirmishers and box them in a corner and get rid of them all that with somewhere between 2k or a a little higher depends on how many you lose.