Not sure if you guy’s got an answer or not. I’ll give you our experience with Gouramis. We have 3 pairs. An opaline pair, a gold pair, and a blue pair. We’ve had them since they were about 1.5″ or so. The opaline’s are our oldest and meanest pair, and are currently in my 125gal with some American cichlids, an eel, a ghost knife fish, and some full size rainbow fish. Oh and my bichirs. Even with these tank mates the female gourami runs the tank. The gold pair are in a 36 and are the youngest pair, they seem to be the more peaceful of the three couples and were beat up by the blues and opalines unfortunately. The blue male seems to be quite aggressive but the female not so much (reverse of how the opalines are) and are in our 55gal with 2 smaller eels and some loaches. We tried them with smaller fish early on but as they grew (more so the blues and opalines) so did their temper lol hence why they are with big fish that can buck back if necessary. So I’d say try it but just have a back up plan if they seem to get aggressive. You guys can ask for more details if you want.