Oda often uses the same hierarchy for powerful crews/organizations in the New World: Captain and the Big Three.
We have seen this with the Big Mom Pirates: Big Mom and the three Sweet Commanders.
Same with the Beasts Pirates: Kaido and his three right-hand men known as the All-Stars.
Same with the Red Hair Pirates as well. Just below Shanks are his three Executives, all of whom have become infamous in their own right.
Even the Marines have this system: Fleet Admiral Akainu and three Admirals.
So what are your thoughts for the Straw Hat Pirates? They are definitely a powerful crew so they are going to follow this trend.
Here are my thoughts: Luffy is definitely the captain. The Big Three are going to be Zoro, Sanji and Usopp. No doubts for Zoro and Sanji but everyone seems to be saying Jinbe or Yamato if she joins the Straw Hats at the end of Wano arc but I don’t think so. Oda has said he likes making weak characters powerful and Usopp has been with the crew since the beginning. I think he’ll be the third Big Three. Especially after him gaining Haki, I can see him being more powerful.
Another reason why I think Usopp is going to be in the Big Three in Straw Hats: his dad Yasopp is one of Shanks’ three right-hand men.