In extreme circumstances Judges should be overruled

The capacity would have to lie with the athletic commissions and not the sanctioning bodies. That's not to say that they would be beyond corruption or incompetence either, e.g., Texas. Also, regardless of the institution you appoint, the line drawing problem isn't going to vanish. However, such difficulties are endemic to any sort of appeal on a subjective valuation. Really, the only workable method would involve some sort of panel that would overturn a judgment on a "clear abuse of discretion" standard, which is highly deferential, and perhaps be required to reach a super majority.