Again thanks for your in put gents, important matters first the GT is eating pellets and the damaged meat has fallen off. So hopefully it will heal up.
I know full well what my fahaka eats as I have kept numerous puffers over the years and I feed them crabs, crayfish and whole cockles and clams which they munch through.
I will continue the experiment to see what can live with her. At the moment I can rule out fish that are too small and motionless (the poor little jag) and the aggressive fish.. The GT which decided to take on a fish 6 times its size. So peaceful fish are the way to go you can see the dithers in the pictures I have already posted and the Oscar who is living quite happily and below is my ornate birchir.. Again no issues.
If a time arises where the fahaka become too dangerous to live with others she will have the tank to herself.