I managed to win this one as the Palmyrene today.
My right advanced on his left, using the marsh areas to protect their flanks. I pushed his Cav back and some damage but nothing fancy. My opponent responded by moving his 3 infantry units forward on his right.
My right advanced again, killing his Light Cav that could not retreat because the infantry were behind them. A Heavy Cav advanced to his Heavy Infantry and was wiped out when it attacked by a First Strike card (my opponent gets those a lot). My other Heavy Cav hit his Medium Cav, knocking it down to 1 block.
My opponent responded by moving forward his right and doing some missile fire.
I played a Mounted Charge and advanced in the center and right again. My Heavy Cav on my right did 2 blocks to his Heavy Infantry and was destroyed. I threw my Light Cav on my right at his Heavy Infantry, doing 2 blocks and destroying the unit (yes, that was very lucky). And I killed his leader as well. Then My Light Cav on my right moved to a blocking position against his Slinger and killed it too. One Light Cav destroyed 3 units in one move. It probably isn't a record, but it was memorable.
The units in the middle did some damage while his Cav units retreated, clumping his units without easy retreat paths. He tried to recover the situation and played Spartacus but was only able to activate 2 Heavy Infantry and 2 other units and wasn't able to clear the clogged retreat paths but he killed the Light Cav that had done so much damage.
I activated 2 units in the center and destroyed 2 units in the middle to win the game. The block count was 23-12 in my favor.