I don't see why it is such a big deal, all of the Cichlids you have tried are commonly tank-bred, and are usually a dime-a-dozen and always instock at petstores.. Its not like hes throwing something rare or valuable in there..
It's also no coincidence that all of the fish that Motag has kept are also common, tank-bred, dime-a-dozen fish.. Experience... Maybe? Complexicity of overall knowledge.. Lacking?
I, for one, have never owned a Snakehead, but I understand their personality just from reading about them and watching videos.. but there are 2 things that set apart Channa from Cichlids.. Chichlids are aggressive because of Territory, and they would rather 'Battle' over territory. Channa are aggressive out of nature, and would rather 'Kill' over territory.. Channa are also equiped with the weaponry to do so (teeth, bite, agility..)..
I too have attempted to keep tankmates with a fish that is suppose to have 'no-tankmates'.. I now have a fully stocked Fahaka puffer tank, after having quite a few casualties, he could care less about his tankmates. Am I cruel and a bad person because I sacraficed a few cheap cichlids that I bought from a corprorate pet store, which were likely doomed for death as soon as they left the asian breeding farm?
Hey Rumblesushi, try this when the wife is not looking..
Take the Channa out, place him in a 5g bucket for a few hours.. Then add about 5 good sized convicts, with multiple hiding spots.. Hopefully you can get a few pairs, because they seem braver in pairs. Then also add a school of 6-10 Giant Danios, at full size.. This set-up should hopefully have enough movement and chaoticness that when the Channa is re-introduced, he will become a little more defensive, than offensive. You may have some casualties, but he also might get tired of chasing other fish. However, with the speed and cunning of the Channa, it might just be a long, drawn-out expensive meal. This is the method I used with my Fahaka, adding a school of large tinfoil barbs with some african cichlids, severums, and a few other fish all at the same time.