There aggression also has a lot to do with there environment you have a nice looking tank with a lot of hiding places that greatly reduces stress.
I have 4 tanks that are cichlid only so I have had time to experiment with there aggression , one fish can make all the difference if he wants to be mean , a good tank boss keeps everyone in check peacefully a bad boss uses anger and aggression out of 40 fish I only had to remove 2 in the different tanks to balance the system.
And I don't believe in over stalking to control.
I have 4 tanks that are cichlid only so I have had time to experiment with there aggression , one fish can make all the difference if he wants to be mean , a good tank boss keeps everyone in check peacefully a bad boss uses anger and aggression out of 40 fish I only had to remove 2 in the different tanks to balance the system.
And I don't believe in over stalking to control.