And just a word from the Kingdoms side of the fence:
Mangonel.
My first battle with one (having not really read the unit description), I targeted an 8-star general on the other side, hoping to dent his scary big bodyguard unit before we got to the serious business. As I watch, the projectile goes up, the projectile goes off midair, and a ball of flaming goo lands on the enemy general and another mounted knight next to him.
Cut to the "God be praised, we have killed the enemy general" scene.
Back to the main battle screen: The bodyguard routs on the spot ... the rest of the enemy army (a vast collection of militia, largely, made imposing by the general's command points) routs w/in about 30 seconds, lock, stock and errr, barrel.
It went from a tense battle to a slaughter in the first shot. Now I know it's not always going to be that precise, but what an introduction.