For those of you having trouble, the key to winning is killing enemies on their half of the map. This earns you reputation which increase your gold income.
The tool tip for the hero's battle slam does not say it stuns the enemy. I thought there was a glitch where my troops were getting stuck.
Ranged units on hills have aiming issues. I just had a battle between my mages and enemy archers and the fireballs all landed right in front of the archers never hitting them.
Lastly I am gaining reputation for my own troops dieing on the enemy's side of the map. I don't know if this is intended or not but the tutorial only mentioned getting rep from killing enemies.
8/10 because it could use a bit more polish.