I'm treating it as a feudal system as well. The Hurricane King is the feudal chief of the entire region. All the Free Captains have individually sworn fealty to him and agreed to pay tributes,.....Most of the pirates smart enough and dangerous enough to become Free Captains recognize that it's better to abide by the Council's decisions than to let petty disputes evolve into open warfare between fleets. If they have a disagreement over, say, which of the ships in a battle has first claim to prizes they can take it to the Council and either work out an arbitration or settle it with a duel or something. You might not get what you want, exactly, but you can expect more or less fair compensation and also that the situation won't escalate into a destructive conflict where everyone loses money.
Hmm, for one I have never seen any hint as to the pirate "king" being a feudal lord supported by vows of fealty and an exchange of duties.
TWOWAY OBLIGATIONS ? A central part of any feudal society ? Usually highly regulated ?
Or even anything declared through divine right ( I do NOT see Besmara and her priesthood supporting such an institution, only everyone tearing it down ). Shifting alliances and a mostly decorative "figurehead" title, yes, but the pirate "king" looks more like a "capo-di-capo" to me.
Second : Pirates are SMART ? Since when ? The entire real history of western piratehood is one of being essentially not "smart" or "wise" or "trusting in far judement".... as is the hollywoodeque one ? Everyone wise either became pretty lawful, once sucess was achieved (say, Francis Drake) and would not be supported (ahem, rather reviled) by Besmara....
All of it sounds very unpiratish to me (IMHO).... "take what you want, give nothing back" seems a far more of a pirate motto than "king of the Free Pirates" ( sorry if I roll around some, laughing)... Doesn't "Free" indicate a tendency for (local) tradition over rule and sensible laws, and a distinct wish to be FREE from such oppression/rulership ?