Let me explain what this theory is all about. It isn’t specifically about the Straw Hat Grand Fleet. That is an army (5000+ strong) that is loyal to Luffy and will play a huge part in the final war.
The army or armies I’m here to talk about are the people that will serve directly under members of the Straw Hat crew specifically loyal to them.
You have to remember that by the end of this series this will be the crew of the King of the Pirates. This crew will have the greatest swordsman, greatest navigator, greatest shipwright, greatest chef, greatest doctor, greatest sniper & so on. They will be no ordinary crew and therefore will inspire their own followers too.
First Sanji:
So first of all I’ll start with Sanji since we’re still in the Whole Cake Island Arc and I think he’ll be the first member of the crew to gain his own followers. Who will they be? It should be pretty obvious that I think it will be the Germa 66. Now people don’t think that this is the case because Sanji wants nothing to do with the Germa or Vinsmoke name however I think Sanji will eventually change his mind. Now this is just pure speculation but I believe by the end of the showdown at Cacao Island the Vinsmoke siblings will come to recognise Sanji’s fighting strength and by the end of this arc after Sanji learns the true history of the Germa he will come to change his mind. What that history is, is extremely difficult to speculate.
Coming on to the more solid reasons for my theory, I have two:
1) Back on Thriller Bark (Chapter 485), Sanji told Kuma to take his life because one day he would become a threat to the world government one day. What better way to do that then to command an mythical army that only mere days ago was under the World Government
2) On Zou (Chapter 819), Luffy said he needed to save Sanji before he could fight Kaido. Luffy said he’s pretty much worth a thousand people and I believe that is foreshadowing that eventually Sanji will come to command the Germa 66 Army which will be approximately 1000 people.
Next is Zoro:
In the same chapter (819) right after Luffy said Sanji is worth 1000 people Zoro replied and said I’m worth 2000 people.
This was meant to be a joke but I think it was more like foreshadowing as to the number of people Zoro will eventually command. In chapter 822, Zoro also went to comment that he’ll round up the Samurai in Wano.
I don’t think that will be the case when Luffy arrives in Wano but when Zoro sees Sanji return with a thousand soldiers behind him I think it will make for a some hilarious moments but also for Zoro to up his game and by the end of Wano he to will have his own army of loyal Samurai.
Now on to Usopp, Franky & Jinbe:
I have even less to say about these three since it’s just mere speculation but I think it still is in the realm of possibility. Usopp has always been friendly with giants. He had great respect for Dorry and Broggy on Little Garden since they were brave warriors of the sea and in Enies Lobby he had two giants turn on the World Government and join him (Chapter 390).
In Dressrosa, Harjudin even ended up portraying him as a God. Whether by some miracle and some huge luck or by his own merit I’m absolutely certain that by the end of Elbaph the entire nation of Giant Warriors will be Usopp’s subordinates. It truly would be poetic if the weakest member of the Straw Hat Crew would end up commanding members of the world’s strongest nation.
Franky I believe will eventually build his own Franky Army rivalling the Kuma Pacifistas. He definitely has the capability to all he requires is the material and the time. I can definitely see in the final war tons of Franky-bots saying ‘suuuuper’ in unison and then blowing everything up.
The fate of the Sun Pirates is yet to be determined. Do they join the Grand Fleet under Luffy or are they a allied pirate crew loyal to Jinbe.
Whatever the case I think Shirahoshi will be busy commanding the sea kings while Jinbe will command the Neptune Army. The Fishman Island taught us two things. First Jinbe was once a member of the Neptune Army & second that the entire nation respects him. Definitely see Jinbei commanding them in the final war.
While this is mostly speculation I genuinely believe this theory will come true. I also believe that Nami, Robin, Chopper & Brook will have their own followers however I couldn’t think of anyone in the story who could become their followers. Maybe as the story progresses we’ll learn their identities or maybe the theory will be proven false. We should find out soon as the Whole Cake Island Arc comes to an end.
Hoped you enjoyed it.
*Theory by Iron Pirate