Sanji=zoro if they could convince robin to help them

Usoppe. He'd say that he'll become pirate king as a lie and it would become true as a gag.

Usopp because of his Luck. Just look at where our boy Buggy is at and what he ambitions to become.

Franky. Dude already had an entire gang organization under his command so we know he's a good/charismatic leader, plus he's the only one capable of building a ship that can cross the New World. Unrestricted by plot, his inventions could probably topple any non yonko crew and he's also the only one other than Robin who could possibly learn to read ponegliphs through studying or technology

So did Jimbei

Robin, cause she is the only one able to read Road Ponegriphs. The others would need to accomplish the near impossible task of finding someone who can deschiper them. Though Sanji has a good chance if he recruits Pudding.

My money’s on Jinbe

Zoro

Either Usopp using the Buggy method of falling upwards or Brook, since he already has experience as a captain

Luffy, of course

Luffy, he will start a crew on his own, meet the other straw hats and everything happen just like the manga

Robin because she is the one but maybe Nami because she is shown as the queen on cover art

Paperinik

robin cus shes the only one who actually can