How about transferable flashlight beating vouchers? That way, officers who come in under their quota can trade with those who use up their beating allowance. The overall number of authorized flashlight beatings remains constant, but more of the flashlight beatings are administered by specialists, so the average quality goes up.
The free market works!
Also, if more than one officer is beating the same guy it only should count as one beating. Not one for each officer but only a percent per officer, like 4 cops one thug = 25% per cop deducted from their beating quota. It is after all only one person getting the beating.