Fractal morphology.

Fractal association in basic structure from separate evolution.

Odd correlation between structures of different morphology:
   All symmetrical and often perfectly circular in shape.
   Powerful, energetic process in the centre.
   A central object (not in clusters)
   That central entity, when found, is often semi-compact.
   All have powerful 'outflow' from or around the centre.
   Hard to calculate rotation of the often enigmatic central object (some super fast, some v. slow).
   Bright, active zone may form around central object in bigger structures that may connect to star forming.
   Grading from the centre to the extremities as a steady decline in matter densities.
   The further from centre, the slower the movement of matter.

If the same entity is found in the centre of clusters and the fast rotation of the super massive objects in the centre of galaxies was in doubt (that is calculated from the speed of gasses and not directly from rotation) then these structures would have a striking correlation in evolution and driven by the same fundamental process just very different in scale.
We get used to viewing these structures without seeing how bizarre they are to produce with the current evolution process.