The game is really good, but I find it too reliant on raw numbers/levels rather than proper tactics and strategy.
The fight mode only works well if you are in proper relation to one another. No amount of Berserk is going to help you if your enemy's individual troops are 5x the level of your own.
Likewise, because there is both a limit on how many units can attack a single one (as well as no benefit to attacking from the back or sides that I could see) there's no real benefit to troop placement aside from making sure they don't get your base. A firm wall of whatever works best for said environment in front of a hoard of archers tends to be the key to victory regardless of scenario or difficulty.
Oh, and why the radically shifting power levels of the nations? If you're on a harder difficulty, a higher power level of a beginning nation can be the difference between absolute failure or victory.