According to Quantum FFF Theory, equal sized black holes are only able to attract each other up to a certain distance due to the repulsive force of the so called " ZPE driven plasma tail" which seems to transform into a " Bar" and two " plasma jets" after a certain approaching distance.
Such equal sized black holes are supposed to form a Herbig Haro (HH) system as an important base for quick star- and galaxy formation.
Both HH- black holes are assumed to be created in supernova explosions, and observed inside HH systems as hotspots or bowshocks.
However if a small black hole meets a larger one, the system is not able to stabilize in the oscillating Higgs field which is supposed to be the start of a splitting process with a gamma burst as the result ( see below).
However it is not clear what the mass ratio must be between two approaching black holes to split or create a Herbig Haro system, OR merge together into a bigger one.
According to the Quantum FFF black hole model, it seems a logic step, to assume that the mass ration of mergers should be smaller than the ration for splitting one of the two BHs..
We know the mass ratio of the LIGO mergers: 36: 29 M.sun!!
Thus only small black holes are able to split much large black holes, up to a certain ratio beyond 36:29.
Still the universe should be able to form giant dark matter black holes in the centers of galaxies by trillions of merging processes as is often observed.
So the centers of galaxies are supposed to create a very complex and chaotic Higgs field, which is supposed to be able to prevent the formation of stable "Bars" and " plasma jets" for Herbig Haro systems and star formation leading to " red and dead" galaxy centers (as observed).
Instead the chaotic Higgs field in the galaxy center will support the black hole merging process even for equal sized black holes.
It is assumed that such merging systems could trigger the accelerated growth of the central galaxy black hole and in succession the formation of galaxy clusters and eventually the big crunch as proposed by Q-FFF Theory.