Are all the galaxies we see just part of a much larger galaxy?
Any galaxy is a part of our universe Our universe is a system of systems of galaxies.. So, any galaxy might be part of a galaxy system in which there might be larger galaxies.
There appears a Milky Way system in which there are some satellite
galaxies. The great neighbor Andromeda ought to have similar
system. These systems belong to our universe that could be
regarded as a system of such galaxy systems.
I think that the definition of the 'center to prevent imbalance', with
to planet system on to star system on to galaxy system on to system
of galaxies called our universe, is understandable.