I have 1gbr and 2 kribs. I used to have 3 gbr but one was lost to unknown causes and the other was a jumper.
The kribs are actually separated. The one was showing a lot of aggression towards the other so I put the aggressive one in my 8gal evolve. The other krib and gbr are in my 20L.
At first the gbr wasn't enjoying sharing his space with the krib and showed some aggression, but now they seem to have grown on each other. They both follow one another around the tank and from time to time the gbr playfully chases the krib.