User blog comment:The ASL Pirates/Traveling Back/@comment-10543621-20150720063525

First point regarding the whole idea of 'claiming' islands and placing them under your protection. From what we've seen, none of the Yonkos are anywhere near any of the numerous islands that are supposedly under their protection. Even in the case of Big Mom 'protecting' Fishmen island, I highly doubt she herself has even been on Fishmen island, except maybe when she travels between the New World and Paradise herself. The point is, the protection rendered by a large crew like the Yonko is essentially based on the name and influence alone, and the promise of 'incurring the wrath of a Yonko' should you attempt to challenge the said island.

Even if the Yonko actually extends physical protection, it would be in the form of placing some underlings in charge as seen with Scotch protecting the island that was supposed to be Kaido's favourite. In other words, what this means is that if Luffy hopes to place Fishmen island under his protection the way the Yonkos protect islands as he claims, he'll need to drastically expand his influence. He would also need to drastically expand his allies/underlings to a level comparable to the larger crews like the Yonko. Otherwise, even if Fishman island waves the Strawhat flag, even if Luffy's name was big enough to be a deterrent, as long as other pirates are aware that the Strawhats hardly have any manpower, they'd know there's no need to fear them if they're halfway across the New World.

Now talking about actually attaining the status as a Yonko, in my opinion, this might occur during the series, but it certainly won't end with Luffy holding the status of Yonko for obvious reasons. He's supposed to become the pirate king. The Yonko were simply 4 greatest pirate crews that filled in the void after the Roger pirates disbanded. They were the 4 strongest contenders to become the next Pirate King. Luffy is meant to topple them all and become the Pirate King. By the time that happens, there won't be any Yonko to speak of.