If we're going to add a new bar, let's go in the direction of GW2: Stability. With CC so stupidly accessible to both the player and Ai, having a stat that ABSORBS a certain number of CCs would be lovely. (I think the number of abilities that have a stun tied to them is around 30%+. That's insane.)
Or, we can just go in the direction someone mentioned earlier and have different CC do DIFFERENT things. Having a character be stunned the exact same way with 14 different color options on top is just silly.