Whole wings thing is just figure of speech, at least here. Hands do the work but wings are more like what pushes you forward
Roughly the same thing; it just puts emphasis on following factors:
-They're both the two main pillars of support for Luffy- similar to Rayleigh and Gaban (Silver and Copper to Roger's Gold)
-They're, well, two most significant individuals to the crew in terms of characteristics and whatnot (not accounting for plot, where Robin leaves either in dust).
Ultimately, it just preserves the M3 nature. It preserves that Sanji is more important than anyone not named Luffy or Zoro, and that Sanji will always maintain that position. And yes, it also shows how Sanji will be strong later on, too. I always saw him on par with any admiral come EoS, tbh.
Since this entire topic is based on story and narrative, I have a question, though. Do you believe Sanji is on par with Zoro on narrative importance? We're not talking about practical stuff (cooking for survivability), because then Nami is much more useful than either anyway. I'm bringing this up narratively, story-wise.
Would you put them at same level in that manner irrespective of combat strength, or would you consider Zoro a step ahead? Because a lot of folks here, including you, have subtly implied as if the wings comment singlehandedly, certainly decides an even narrative importance.