im going to be completely bias here, but for a genuine reason!
i think clubs like the channa club is useful as there is only a small selection of people know anything about them so its easy to go there and the chances are higher of getting a decent answer to any question, i think ones like livebearers and catfish and so on are a load of rubbish as its easy to gather information on fish like this without the use of a 'club'
this is just my opinion mind, but i agree it should be put through the mods first so as not to cause disagreements on wether they should be there or not.
to my understanding, there is a catfish section, so no 'club' needed, there is a live bearer section, so no 'club' needed, there is a new world cichlid section, so no 'oscar club' needed.
when you go into 'oddball' and 'predatory' fish, this is less specific, but instead of a 'club' i think it would be easier for the mods just to create and open sub-forums more specific to the species becoming more popular, like snakeheads, arowana etc.
just my few thoughts!
Dave