I'm usually an advocate of mixing Africans with other fish, however some of those are likely going to be a bad idea...
-Ropefish might be okay, assuming the get enough food
-Dragon gobies are likely to get picked on and starve
-African knife is in the same boat as the ropefish
-African butterflys are really mellow, and likely to get picked on by curious cichlids
-Jardini aro, would probably be cool in a larger tank, until he starts eating stuff...but Africans are pretty quick.
-Pleco's fine
-Redtail sharks are usually fine too, good algae-eaters and mean too
You may run into issues having only 6 Africans, they do best in bigger groups to spread out the aggression. Personally, I think the knife, ropes, dragon gobies and butterflies would do better in an oddball tank on their own.