It depends on where the individuals are on the psychopathic throughlines.  Full dose, full spectrum psychopaths where each psychopath believes themselves to be a Mutant X superman and lacks capability of restraint cannot interact successfully.  The world is not big enough for the both of them.  However, those who aren’t full dose and can read the food chain and accept their place on it interact all the time, backing each other up against the normy world.  I’ve seen two types of clustering:  the first on pure dominance, the second around successful psychopaths who move more easily through the world of normals.