Buddy of mine and I were just talking about this over the weekend. We are amateur astronomers, and were out observing. I was looking at NGC 2419, a Globular Custer that is so far away that it might just not be part of our galaxy at all, but, just floating between the galaxies in the local group. We postulated that if the universe has an abundance of these clusters, many very small (NGC 2419 is fairly bright, but, is larger that many of the custers around the milky way) then the universe could be fairly full of these things and we wouldn’t know it.
Photographs show that most galaxies have an abundance of globular clusters ‘halo’ed around them. No reason to suspect that there aren’t more free floating.
I think a globular cluster is a proto-galaxy trying to organize itself......................