Maybe the competition needs to be for "Suckers", that will stop any confusion
Maybe the contest should be for suckermouth catfish?What about the sucker fish which are classified as loaches, eg Gyrinocheilus aymonieri? And stiphodons? They are "suckers" but not Loricariids.
What area would twigs (Farlowella sp) and whiptail catfish (Loricaria sp) fall into if not suckermouth catfish?