I have a 220 gallon with two 7 year old adult male severum, 1 Red Head Tapajos, 1 red tail shark, and 1 common pleco. The severum I got together as babies. They bicker back and forth some but did not do well when separated. I’m curious if I add some type of a schooling fish like giant danios or something if that might cut the bickering down a tad and add some more movement to the tank. I’ve also considered adding more red head tapajos but I don’t really know what would be best.