Dunno where Maim and Darkside alleviate the tank stance penalty either, considering that you have them up while not in tanking stance too. The tanking stance is still a 30% damage loss compared to DPS stance for a WAR (Defiance + Deliverance loss), and a 20% damage loss as a DRK. PLD suffers more because of 20% damage loss + ~12% damage loss from the auto attack bonus in SwO. Maim and Darkside have nothing to do with all of this. It's not like unchained.