I've seen people keep all sorts of different cichlids together, but in general, most large-growing central american cichlids do not play well with others and you tend to have aggression problems or fatalities when keeping just a few fish in a medium sized (under 100 gallon) tank. Most people have better luck starting with a group of 6+ young fish at the same size and age and growing them up together. You still might have to remove a fish here or there that is getting too dominant or getting picked on.
In my opinion, you are better off with fast moving dither fish like silver dollars and tinfoil barbs mixed with cichlids. Keep a group of four or more of them and they rarely sustain much damage or cause any. The more aggressive fish will chase them a little, releasing a little steam, which often helps them be more tolerant of other tankmates.
One of my favorite tanks ever was a 360 with a big red texas-looking fish that I think was red devil x managuense, a female red devil, about 8 tinfoil barbs and a redfin gourami. That was before the days of digital cameras and no photos have survived. I raised some babies from those cichlids but none had any pearls and they all just looked like mi-devils.
