I'm guessing the one in the pic was a drawf since I have three of those in my tank. The pearls will get A LOT bigger than the drawfs, so I'd either set up another tank with atleast three or more pearls, or add in two to four more drawls depending on the size of the tank. I have threegourami's in mine (two powder blue one fire red drawfs) and there were some chasing, tail nipping, and head butting by my fire red, so I added in one more powder blue and the fighting has gone down exponentially.
One of your gourami's may be more aggressive and territorial than the other ones as well. I find that dwarfs for sure are either agressive of extremly passive.