Beautiful jags in that tank. The tank seems a lil overstocked but honestly that's not a bad thing in this situation. Atleast while it's overstocked it allows them all to live together without the risk of any one fish being able to control the entire tank. The butti is definitely doing a good job as the tank boss too, he isn't being overly aggressive with everyone else instead he is helping to keep the peace.
I will say this tho, I do agree that personality really does play a major role in if a fish will cohabitate with others. Ik I've had 1 FH where it was impossible to house him with another fish. He would always go around and kill everything in site regardless of size. I tried giving him feeders a couple times just to find out that he didn't want to eat any of the minnows, all he wanted to do was crush their heads and spit em out as he would move onto the next one. Currently I have a 8in female FH that will try to kill any potential tank mate I give her but her sister who is 5in gets along fine with a kirbensis and a Chinese algae eater.
