I like them, but I'd prefer to see self-destruct protocol locked behind contract payout rather than starting on a (high) cool down.
Either that or make the cooldown even higher, but give a mechanism to reduce it much more quickly. For instance, CD = 12 but every time IG-11 uses a basic attack subtract 1. That way if you get called to assist (Greef, Bossk, Mandalorian) or gain Retribution (Greef, though you could also put in non-BH toons to help) and counterattack you burn through the CD much faster.