It’s purely because of the ideal that Sanji won’t keep up with the monster trio.
If Gaban is stated to be even a bit close to Rayleigh it breaks a lot of headcanons cause it means Sanji will still be closer to Zoro eos which unless they think Sanji grow faster than Zoro at this point, means Sanji and Zoro are still close now and King doesn’t mid diff.
If Gaban is stated to be even a bit close to Rayleigh it breaks a lot of headcanons cause it means Sanji will still be closer to Zoro eos which unless they think Sanji grow faster than Zoro at this point, means Sanji and Zoro are still close now and King doesn’t mid diff.
EoS Sanji = Kizaru lvl or slightly above
Thats my guess