TheGreatDirector
Banned
Question: why do they stick to the specific number of warlords? If they have another war lord they want to hire....well, can't they? Why limit themselves?
Same thing with Yonko. The Yonko aren't a job, they are a title. What happens if another pirate of their level shows up and starts conquering? Are they going to change the name just on that?
Marines are probably afraid of having too many warlords. In reality they keep them around for their names more than their actual power. The fear of these powerful pirates being on the World Government side is supposed to discourage other pirates. Having too many warlords might make the Marines too dependent on their strength.