I would think that a system similar to diminishing returns, should be developed to handle all the AoE stun/silence/fear CC that is prevalent in wow these days. I propose something like how the AoE Damage cap works. Say you have a 5 second AoE stun. I would like to see it where if the spell affected two people, they each get a 3 second stun. If the spell affected 3 people, they each get a 2 second stun, 4 people would each get a one second stun. Obviously the numbers are made up, but you get the idea. As it is now, even non boxers can get grouped up in tight areas (AV towers/bunkers) and AoE CC is more powerful, where as in larger BGs and open areas, the AoE CC only really affects boxers.