+50% attack power is not 50% more damage, and warriors with defiance up makes them do -25% damage, and i dont see any other buff they can pop to increase their dps, they can however decrease slashing resistance by 10% ... they better have 5 more damage in their weapons has they are already losing 25% of their damage to tank for you.
berserker (+50% attack power) and internal release(20% crit) thats the only buffs available to warriors.