The size tank should be adequate for those 4 sized cichlids. But.....
The potential problem that jumps out to me, is all 3 cichlid species similar body shape, similar color patterns (especially the iridescent spots) and similar feeding mechanisms (mouth shape), suggesting similar feeding regimes.
Because they all look so similar, the problems associated with territoriality may become enhanced at maturity.
When trying to construct a cichlid community, I find combining cichlids with "dissimilar" shapes, colors, feeding preferences (mouth shapes) etc etc seem to offer the best chances of success.



Above are 3 geographically diverse cichlid communities that worked for me.
left, S American Crenicichla with Guianacara, body and mouth shape, color patterns radically different allowed for them to ignore each other in a 150 gal.
middle, different body, and mouth shape indicated that these Central Americans, had totally different feeding preference, so problems were few, although at maturity they easily outgrew a 6 ft tank. The bocourti vegetarian, intermedia insectivorous, and mollucavores.
and same on the right in a Madagascan cichlid community, different body and mouth shapes, different colors kept them peaceful, although again, at maturity they needed a much larger enclosure that a standard 6 foot tank. The Paretroplus snail eaters, Paratilapia generalized predators

Above, the Madagascans required a minimum 400 gal enclosure in the end. and did fine until
I tried introducing 2 different (but similar appearing) species of Paratilapia in the 400 gal pool, and they sought each other out in that space (as competitors), eventually requiring separate quarters.

