Based on what, the similar parses that both Drk and Pld are putting out in their DPS stances?
Put some things in perspective here...
150 Heavy swing, 200 Skull Sunder, 280 Butchers block = 630 potency
150 Heavy swing, 190 Maim, 270 Storms eye = 610 Potency...
150 Hard Slash, 220 SpinningSlash, 300 Power slash = 670 Potency
150 Hard Slash, 250 Syphon Strike, 280 Delirium Blade = 680 Potency.
150 hard slash, 250 Syphon strike, 400 DA Soul Eater = 800 Potency...
Lets say a Warrior already is under Maim and someone else is applying Storms eye for him. His strongest combo then is the BB combo.
He runs that twice (1260 potency), then does Heavy Swing and Skull sunder (1610 Potency) all together... Now he has 5 stacks and hits Fell cleave (2110) Potency. 2110 Potency after 9 attacks.
The Drk comes in, again someone has applied storms eye for him already.
Dark arts Soul eater combos three times for 9 attacks as well for 2400 potency.... aka 13% more. In raw Potency the warrior is losing out.
We certainly can also consider Berserk. We should also consider that Fracture is 300 potency and Scourge is 500, aka 66% more potency... We'll also have to ignore the DRKS off the GCD attacks such as Dark Passenger, Plunge, Salted Earth,reprisal, etc....
Warriors have burst damage. Fell Cleave being nerfed would be be very ignorant. If theres a real advantage here its partially in equilibrium giving back TP. The Drk is going to tap out earlier unless a DPS gives him some TP to use and then he'll end up Unmend spamming.
Granted in actuality... If this was set-up with a Drk and War both aiming to DPS at the same time. The war would have to get Maim set-up and have to deal with the reduced potency of the Storms eye combo and the Drk would benefit off the warriors Slashing debuff, while having Dark sides benefits from the very start.
Tank damage difference is not large at all. Theres what a 910 parse of Drk already?