Dreadnought cannons/juggernauts really, really, really hurt. Cannon shots rip straight through lines of troops for heavy damage. Juggernauts can bombard you from a distance. The AI moved them out of the city which, at first, seemed pretty retarded, but then the juggernauts did a self-AOE attack which was devastating, and then bombarding thereafter, alternating the spells for max fuck-you points. The Fire Dragon chilling out on their walls more or less singlehandedly won the battle for me. He was resistant to Dreadnought fire (cannons still hurt) and he could fly around at will, flanking and 3x-hitting enemies. I also had a battalion of 91-hp human knights. Warlord gets some hefty bonuses to troops - possibly the strongest in the game...? And Trebuchets proved surprisingly valuable in unit-to-unit combat.
I'd post a picture of the after-screen, but there's something of an easter egg in it that I don't want to spoil.