I think that the counter-attack part was designed so that as a confederate you get to have a field-day. I did this battle today as well (although on medium difficulty) and it was so easy to completely outflank them with the fresh reinforcements. I could've probably done the same on hard difficulty as well, although I'm not sure about the first day fight, for me it got quite close couple of times, but just managed to keep my defense from collapsing
I think that the counter-attack part was designed so that as a confederate you get to have a field-day. I did this battle today as well (although on medium difficulty) and it was so easy to completely outflank them with the fresh reinforcements. I could've probably done the same on hard difficulty as well, although I'm not sure about the first day fight, for me it got quite close couple of times, but just managed to keep my defense from collapsing