First, Bounty Hunters are enemies to Hellfire, so they dont use Arbiter. Well normal BHG ID dont allow battleships and the core one doesnt allow if on a system with a jumpgate. Perhaps inRPly who would get that, maybe the bounty hunter defect to the Legion and going back? That would count as treason.
Second, its tech isnt compatible, and you would be flying with 10% core if you had a BHG/Core ID. Unless your a Core ID that have SRP application approved (its very unlikely)