Hi Leafmite. They have a hierarchy. As long as they understand their place they are peaceful. I have 4 in my 75 gallon. It used to be a 29 gallon, and they were the same 4. There are a lot of fish, but they mainly are on the bottom and the middle. My bottoms are loaches, 2-dojo, 5-yoyos and 4-kuhli, 2- brunocephalus, 3-farowellas, and 2-corie cats. 12 glass catfish. 5 pristella. 4-zebra danios, 4-endlers. There are also 2 blackwidow tetras.
They get along with all of them. No problem. except for the dojo loaches, the fish just stay out of the way. The danios and the dojos are playful and tend to bother everyone, but the daniios are too fast and the dojos are about 3 times as big, so they really rule the roost.
I have a Cambodian female who is slightly aggressive. She will flare occasionally. There are so many places to hide in a 70 with plants that it hasn't concerned me. This is the bad girl. I think it is all about sorting it if it is aggression or normal territoriality which will not be stoppable, except by moving the fish (unless you know how to clicker train them.