I have 8 gouramis in my planted 55 gallon. 5 powdered blue dwarfs and 3 honey sunsets (the flame dwarf died

) all male I believe and they live together just fine. There was aggression at first, some light nips and slow chases but no real damage was done. I read the more the better like in pet stores that get away with having 20 males together. If you get 2, they could surely fight to the death but if you get more than 3 they will spread out their aggression which they have and they established an order by now. In my experience with dwarfs, the more the better. I haven't kept pearls yet but always read they're the most peaceful of the species.