I actually did the exact opposite. Used archers with + armor damage equipment to break armor (most of them are low health units anyway, so I figured this was the best way to use them), and then melee guys to finish them off. I remember finding an item that gave +3 break armor and for the rest of the game used that on Rook. Could take down even the toughest dredge really quickly this way, with an armor attack by Rook, then using one of the high health low armor varls to slice through them like a butterknife.
Oh wait according to some dumbfucks with extreme OCD the best way to play the game is to attack the easy enemies, leave them with 1 HP to deprive the big enemies of turns, and only then attack the big bosses.
Rather than the common sense approach of just killing off the big bosses first.