Not true, I have an eight inch male Butti in a tank with 15 blue zebras, 2 red, 1 pleco, 2 jeweled and four red blood parrots. It's been that way for six months and not one death. No signs a distress or sickness.
might work out for a while but I would consider a single specimen tank for the butti I know this sounds unappealing but its really not found I actually enjoy one fish in a tank (dovii)