Others, evidently, kill dovii twice their size on a whim and would require a flooded basement to possibly accomodate a single fish
Where did I say flooded basement, oh you just add to posts as you see fit. I have had black nastys for 20+ years so maybe I just speak from experience. Maybe yours are hybrids from walmart and thats why they are so docile. Every one I have kept and I have never even tried a pair in a comm. tank whether they were introduced first last or in between was as an aggressive a cichlid as I have ever seen. They have grown anywhere from 10 - 15 inches. Have I seen them kill dovii...no but I have seen them attack jags,devils,midas,flowerhorns etc. and thats why they are solo. But what do I know!