Dual Chainsaws? Seriously? Look that up in the dictionary and you'll probably find the words "See also: Overkill".
Dual Chainsaws (and, indeed, dual Shotguns) is too much. It would make it way too easy to finish the game. Imagine AoB with two Chainsaws (or, as being able to dual weild Chainsaws would have to allow you to dual weild all melee items (dual weild HEAVY Chainsaws but not lighter Combat Knifes or Cleaver/Longinus combo) a combo of the Butcher's Cleaver and the Longinus Spear). If ANYTHING gets nearby, it gets ripped to shreds. It's all about balance.
edit: Ah, after seeing Malek's post, I understand what you're trying to say. Forgive my sleep deprived mind.