Being someone's wings means that you are important for him and that's it.
If Oda wanted to portray Zoro and Sanji as rivals they would take on enemies that are equal, they would both have very good feats, they would be Supernovas together, they would've fought the Yonkos together, at the end of one arc their bounty would be almost the same if not the same, they would've got shared power ups at the same time such as CoC and the most important part, they would have a shared goal or ambition. Like fr, Sanji doesn't even fit the requirements to be Zoro's rival...
Rival: "a person or thing competing with another for the same objective or for superiority in the same field of activity."
Just compare that "rivalry" with Goku/Vegeta, Gon/Killua, Naruto/Sasuke, Light/L, Ash/Gary... Hell, even Goten/Trunks are more rivals that Sanji and Zoro will ever be.
[automerge]1626959738[/automerge]
Rivalry is competing for the same thing however Zoro's and Sanji's goals aren't the same so...
For god's shake, finally someone that knows what a fucking rivalry is.