That's something i have also been thinking about i think there should have been 1 or 2 bounty hunter organization that can even take out guys with 1 billion plus bounty 
Like having them attack the warlords at this moment or sneak in once or twice where Luffy goes to try and claim the bounty would have been cool
The strongest bounty hunters we have seen would barely beat someone with a 200 million bounty
Like having them attack the warlords at this moment or sneak in once or twice where Luffy goes to try and claim the bounty would have been cool
The strongest bounty hunters we have seen would barely beat someone with a 200 million bounty
