I'm not even talking about their mass gravitation, I'm saying its possible that central singularity has some sort of unknown gravitational effect that ripples outward. When you talk about dark matter, you cant limit yourself to conventional gravitation theory. Maybe the SMB's are the heavy neutrino/WIMP source just as our sun is the source of the neutrino's we detect. We still have no clue what happens at the center of these singularities.