Well, im a "nanogimp mp" and tanking a mob in the usual missions we all do isnt any problem now that the healpet paths quite good, depending on the team composition and the situation ill actually work hard to keep the aggro on me, cause the healing from my healpet is for free (4.1K hp & 4.3K ac unbuffed)
And since mindquake does a -100 nano skills debuff, its not that hard to pull aggro with it when u cast one every two seconds while shooting with ur gun (nova in my case), if need be ill throw in a damage debuff to get some extra aggro (Curse of chronus if someone else is taking too much damage, since CoC is so good at pulling aggro)