No one fights cops at long distances.
A lot of corporals? Yes. Active corporals? No. Regardless the vest provides virtually zero more protections to a cop unless they are fighting at a long distance, even then that protection is only a very small increase.
Only time t3 makes a difference is when you're fighting from far away, most fights on olympus are cqc and both vests take the same amount of shots until you start shooting from long range.
Give corp t3, there is literally no difference between a t2 when it comes to fighting on Olympus, yall just don't want it to happen just to spite sapd.