Theory How do large crews like the Yonko manage to get to any part of the ocean they want quickly?

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I don't really understand how it is that the Yonko who live in the New World seem to be able to get to Paradise any time they feel like, or even how they go backwards on the Grand Line? Since Log Poses only point in one direction.

Does every single ship in their fleet have an eternal pose for every single possible location?

And every one of them goes through Fishman Island every single time? What does it even mean for Fishman Island to be "owned" by Whitebeard or Big Mom if their biggest rivals are just zipping through it all the time? And how could it be that they "hadn't seen any pirates for a while" if these giant fleets with hundreds of ships are having to cross on a pretty regular basis?

And they never bump into each other? Like when Kaido and Whitebeard and Shanks were all trying to go to Marineford at the same time, there was no concern they might reach Fishman Island at the same time and totally trash it?

Is this just something that's unexplained or is there some explanation i've missed, like they have specific routes they own and Fishman Island is just for "regular" pirates crossing?
 
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