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.
As an avid GW2 player I must say this is redundant; both player stability and boss break bars essentially work in a similar manner to the magical;/physical armor we already have. You have to strip every stack of stability with a CC attack to get your CCs to take effect if it's a player; if it's a boss, all soft and hard CC drains the breakbar until it empties, at which point you get a stun and a increase in damage.
DOS2 basically uses the same system as a breakbar, minus the damage boost once armor is destroyed, allowing us to be CC'ed instead.