I think buggy would accept such a position but for different reasons. I think he is dead serious about wanting to be a pirate king or whatnot but the truth is and he knows it that he is not strong enough. His crew has level 5, 4, 3, 2 and 1 prisoners which makes it monstrously powerful, it is by all intents and purposes a massive military force which could easily break havoc anywhere in the first half of the grand line. Thing is, he should be aware of the level of power people in the second half of the grand have along with the power of strong marines. In that sense, he is very well aware a single other shichibukai, a single VA or above marine or perhaps even an average NW crew (depending on the power of the crews there) could annihilate the lot of them. A shichibukai title works for the marines and buggy. It helps to keep the WG from buggy's back and it helps the WG by keeping buggy's crew in check.