One other thing I believe I should mention, is the intimidation factor., that may thwart growth.
You may recall in your other haitiensus thread, I may have mentioned some haitiensus fry out growing others, or even simply causing others to drop dead for no apparent reason, when in the presence of other haitiensus.
I never saw overt aggression, but many died.
I believe there are ways they intimidate others of the same species into a point where they simply die.
Although I have no scientific basis for this, other than observation, and in the TFH article, the author suggested enough intimidation stress was placed, that he separated all individuals, to the point of using caves within compartments so as not to allow constant visual contact if the fish so desired, (although some intimidation may be hormonal/chemical cues) , and some be be hogging all the food, etc, there are many as yet "not" understood factors in inter-cichlid communication.