The theory of all male tanks working, as a concept seems to go well for African cichlid keepers because in the rift lakes, diverse flocks of varied cichlid species exist together like that in nature. And in standard size tanks, like 55s and 75 it is a very common technique.
Cichlids in Central America do not have those large inland seas with seemingly unlimited space, so in comparison and have developed less tolerance, more jealous attitude toward sharing the neighborhood turf.
I've not found that all male communities to translate into the new world cichlid realm. especially with the Central American, and/or South American species from west of the Andes, where much fewer species share habitat.
Tanks for new world cichlids need to be much larger to accommodate diversity, than African cichlid keepers have the luxury of getting away with.
For these less tolerant American's, tanks of 300-500 gals may be needed to keep from being battle zones.
There are some new world species that have evolved a shoaling and sharing of space tolerance,.
Some Thorichthys come to mind where a couple different species of a genera are able to share a limited area in nature, butt most don't.
In a habit in nature we often see only 1 domient spent, or 2 if the acreage is large enough.
It may be about selective combinations of species rather than all male generalizing.