Part of the problem is for dual wield the char screen isn't accurate. You are probably closer to 250-275+ in all actuality.
That is not true. From what I understand, dual weild gives 15% attack speed, and the game calculates it by multiplying the dps of each weapon by 1.15 then averaging them.
Now, you could make the argument that it doesn't clearly show the dps of his build, as WW build gets the majority of its dps from the mainhand, but the dps is correct for just straight attacks with no weapon mod dmg.