I must say this. If ANY of the chain fighting dogs I had were like a Robert T, I would just accept my fate, keep the dog, breed him and see what goes where. None of mine were Robert T. Hell, they probably weren't a hair on Robert T's nuts.
Ultimately, I would go with performance over habits if it were a chain fighting or hole digging retard. I can fix hole digging with a concrete spot. I could fix the chain fighting with one of my pens. Either way, dogs such as Robert T, or any dog with such abilities, is worth dealing with to possibly harness what they are/were.