I have to agree with Scotty, what a bunch of BS! Raised together in a group tank those mbuna will be fine. As for Red Zebras vs. Auratus on agression levels you are talking apples and oranges. The Auratus is quite possibly THE single most aggressive of all Malawi mbuna species commonly kept!
If you have a good aquascape with plenty of rockwork and such you will be just fine with those fish! Also remember that African Malawis and other Rift lake cichlids come from and do better in Crowded conditions! Crowding helps reduce aggression not add to it.
My worst scrapped ( currently isolated til the rest of the fish can grow a bit larger ) is my larger Damasoni! It is a brute! As for Zebras ( reds are my favorite and I have more of them than any other species ) they can hold their own and are okay scrappers, but they are not even close to species like Johanni, Auratus, Damasoni, etc. They are a more midrange fish like Kenyi for example. My most docile fish are probably my Labidichromis.
Also there are tricks that can difuse aggression in tanks. If the tank is long then certain species of fast swimming fish can help to bring aggression down drastically. I use large danios ( yes I know that they are not Africans ) to quell a lot of tank aggression. A fast moving small shool races back and forth in my tank and they can swim rings around my Africans. But they do tend to break up tension in the tank. This can also me done with a small school of certain types of barbs.
Anyway, listen to Scotty, because most of the rest of the posts are the stuff one would fertilize the lawn with! Crap. Best of luck to you!
- Erik -