Auto-resolve would've done well for that fight? I had decided, randomly, to give myself build time, so marched into that fight with all armies (and my sov). My sov died first round after taking 30 unexpected damage... my armies slowly overtook the boss. Nothing gave me any trouble except the boss, who I couldn't manage to hit and who could hit me for 30 consistently.
Finally one of my "golden hammer" forces (maxed armor + warhammer, unit of 8) hit him for 96 and that was the end of it.
Anticlimactic... but worse konwing it would've been easier to just autoresolve!