I think anyone who get into the hobby sooner or later ends up keeping RTBS's they're pretty irrisistable really , and quite beautiful to observe ,but they can be little devils
I do think that Botia type loaches are ideal tank mates though , as they are strong and can defend themselves if nessesary , i did once try 6 in a 48x24x18 tank of mixed Botia's and it worked for a while because the tank was saturated with hygro polysperma plants , so disputes could be avoided by simply dissapearing into the jungle ! my problem started when I over pruned the tank and the plants never grew back as they were , leaving the Sharks out in the open to spar
anyway I ended up taking them to a local shop , they had grown well too
Though I haven't tried any for years I have a few Red Finned Sharks , and though they will have the odd tiff they are'nt as feisty as red Tails
though they do like a bit of space ,and are a bit territorial .