Ha Ha Ha, i did the Whole Tiger Barb thing too.. and they were disasterous... ended up giving my other fish away and just getting more tiger barbs, they are a great fish but not a great community fish.. I have 6 of them in a tank along with a Rainbow shark... he is in there because i was told they were community like Bala so bought multiples for my bigger tank... then had to move one.. he gets along fine with the barbs, and they all leave the Clown Plec alone. But the Roughed up Tetra definitely sounds like the barbs got to it. I found that adding more hiding places for the other fish helped with agression a little bit, but its a finite space and eventually the Barbs learn where the other fish hide.. Anyway, my advice would be move the Tetra and get replace with Tiger Barbs, if you have room in the tank.. they are great fish to watch.