People would have Buggy and Shanks as rivals/equals if they had their way, we can see them arguing and fighting etc and all that. The thing is that having these fights between the second and third strongest helps keep a certain balance so as not to pit the captain and right hand against each other which is what shonen readers most likely do, we love to compare. Just look up all the debates and threads and you can clearly see that people are more interested in these sort of things. We can see how Jinbe joining and possible Yamato joining the SHPs started all these speculative discussions about their standing in the crew in terms of strength. Start removing all the Zoro and Sanji competitive interactions and you will see how unenjoyable the manga becomes. It doesn't matter if it is a shonen trope etc. the thing is that the manga needs this to be enjoyable as a whole.
Doesn't matter how closely they are depicted the truth is that King is the second strongest, the right hand of the WSC who leads the beast pirates and all stars, someone who has not lost until now and his strength/endurance/durability has been hyped by both his captain (who changed his name to King after seeing his strength) and his supposed rival/equal etc. as being a monster. While Queen does not have any such hype from Kaido/King/Jack etc.
Doesn't matter how closely they are depicted the truth is that King is the second strongest, the right hand of the WSC who leads the beast pirates and all stars, someone who has not lost until now and his strength/endurance/durability has been hyped by both his captain (who changed his name to King after seeing his strength) and his supposed rival/equal etc. as being a monster. While Queen does not have any such hype from Kaido/King/Jack etc.
