Their biggest problem though, would be to find someone with enough power in their name to replace him. The Tryant Kuma is a name pirates know and fear. I mean even someone like Luffy, with all his feats of invading and pretty much destory all 3 of the world goverments main islands, damn rooks like Caribou reckon they could take him on. While Luffy has a name, it isn't much to scare off the stronger pirates of the day. Even Law had to go out of his way to make himself stand out (appearing at the war and saving Luffy, 100 hearts etc). Buggy is a simpiler one as he has history (even if his unworthy), was at the war, and has been shown to be a comander of a group of convicts of some significant strength. Much like the Yonkou, his crew is filled with bounty headed pirates, who's numbers alone would scare off opponents. Who knows, maybe even Caribou was after joining his crew.
ace got a nod early on. there are plenty of pirates out there that would be strong enough that i doubt we have ever heard of. who knows you know i mean its also about power to. i mean black beard had no name in till he took down ace. it only takes one act to get famous then you let you power do the talking for you.
Ace is a different case. He was openly roflstomping all his opponents. He didn't struggle and, unlike Luffy, his feats were hidden from the media (i.e. taking down Croc and the real reason behind him rampaging at Enes Lobby). Don't forget that Ace, even without haki, fought on par with Jimbei. None of the supernovas, pre-timeskip, would have been able to do that.
Originally Posted by cross777
BB had no name, but he was a former WB crew member. That and he managed to take down Ace, WB's current Top Dog. Don't forget that WB was pushing Ace to do all the work, as he wanted to make him the next PK. Marco, himself and the other captains were taking a break from it. Ace was always in the limelight. Then again, if anyone could take down Marco and Jaws, they would have been placed in the Shichibukai as well, had they wanted. I mean we're talking about people who can hold their own against an Admiral, now many people out there can do that.
so, like i said it only takes 1 thing to make it big and like i said then you power does the talking when you ripping through fodder left and right.