I agree with this fully, maybe i wanna add that Oda can do better in dividing which powers he should give to SHs. If Oda design Luffy's affinity and effort to train CoC, he shouldnt give FS or barrier CoA to Luffy imo. If Oda didnt feel like giving Luffy AdvCoC yet, Luffy just learning internal CoA without being able to do barrier CoA would felt specialized enough. After that Oda can go crazy in AdvCoC but should also make Luffy invents a completely original power unique to him that no one else in the world have. Compressing his body nerve or joints to produce FTL reactions, freely compressing and releasing any kinetic energy, you name it.
On the other hand, if Zoro is specialized in CoA, Oda can always make Zoro's barrier CoA stronger than Luffy's hardening CoA until Luffy found out and learned internal CoA which Zoro can't do. If Luffy would be the CoC specialist, Oda didn't even have to feel obliged to give Zoro release CoC (like in chp 1010 Asura) let alone AdvCoC (that Zoro may get in upcoming chapters hypothetically) that Luffy has,but Oda can give Zoro max barrier CoA and other kind of mystic powers related to Asura that apparently can pave the way unto Black Blade, or rather as the beginning of an original spirit-related power unique to Zoro. Lush-Green CoA Blade that has its own spirit and exactly cutting the enemies weak point? Some epiphany in attaining absolute calm or strike precision in battle?
...while only Sanji should get FS. Lufy doesnt fit that at all.
So each one have his strength and weaknesses, it felt more specialized to me. And it should apply as well to their fight, since i felt Zoro interfering with Luffy's opponent doesnt fit the theme at all. If Zoro is fit to slay a dragon then dont give Kaidou a dragon fruit lol, give him something else that represents WSC like a Titan race and More More DF (like Burndy World) or something. While King or Orochi can be a master swordsman that also has a dragon DF for Zoro to slay, this way no one interferes with each other to prove a point.