Dont see why it cant check upon logging/ zone changes/ level up what feats a person has and set the number of hooks in each animation in the chain, no calculations need be made during combat this way, you're either 'flagged' for an offhand hook on this attack or not and, for monks and pallies, they dont have to play the guessing game of 'will i get a double proc from this attack when i smite.....****, maybe next time' which i foresee as being very frustrating and leading to an even further dps loss.
I still havent seen any proof of TWFs deserved damage nerf, if it needs one, fine, but i really cant get behind the random chance for offhand attacks thing