I think your trying to incorporate GTA V's online functions, though it may be a good idea it would ultimately make the game very competetive and thus ruining its primary focus of co-op gameplay as players will be too busy killing bounties and thus making enemies all the time. If you want to settle something dont put a bounty on the opponent for somebody else to kill, settle here and there with your own 2 hands and show them you have the will to fight on no matter what the odds against you...