Mixing aggressive cichlids with community fish usually does not work. My Africans occupy the whole tank top to bottom. The only fish I have that really have any kind of space they spend the most time in is my Synodontis African catfish which hardly ever strays from the bottom unless being chased by one of the African male cichlids. I do not think it would for long, once the Cichlids established territory I do not think the Rainbows would have much of a chance. I am sure the Africans would not work, I am not sure how the SA cichlids would take it. I agree with Thyra on the level of the tank a fish hangs out in, its not real accurate unless talking about a catfish and thats not always 100% either.