He could still only target one grid per turn, without quickness. So against most everything, having those extra attacks would only deal more damage. While overkill works against few critters, I'd rather equip my Nataraja to be able to fight for a long time and with little risk.
This doesn't mean Nataraja with Astral Weapon sucks, mind you... But he can do just fine with 2-3 weapons. Now, Nataraja with two Bows of War Astral Weapon...
(I don't know if it would work).