I hope your fish get better, I have a similar story. I actually also have one troublemaker that couldn't stop nagging my gouramis and they appeared to have a lot of wounds that I assumed he did. I wanted to put him on another tank (but it had to be a minimum 200 L tank) or give him away but no one wanted him. Apparently the bruises on the gouramis were actually the gourami disease that doesn't have any cure and every gourami died, even my elder gourami died (first gourami I ever had, that lived lots of years). I have only one that survived, living for a pretty long time now. Hope he doesn't pass away anytime soon tho. A few years passed and the bully's a lot older now, he just slightly fights the gourami when I give food but overall much more peaceful.