You can also realize this by having an IQ about 73 and realizing that Oda isn’t going to randomly introduce 14 characters above admirals.
Why not? Oda is crazy like

he introduced 2 random characters Admiral level during the Timeskip in Fujitora and Aramaki

he also introduced a bunch of random Supernova for Sabaody

Oda loves introducing a bunch of random characters out of nowhere

he also introduced Yamato out of nowhere
 
Why not? Oda is crazy like

he introduced 2 random characters Admiral level during the Timeskip in Fujitora and Aramaki

he also introduced a bunch of random Supernova for Sabaody

Oda loves introducing a bunch of random characters out of nowhere

he also introduced Yamato out of nowhere
There’s a difference between introducing two replacements admirals after a time skip or showing other pirates and introducing 9 Yonko/admiral level characters out of nowhere.

That being said, the captain of the holy knights Banks probably will be stronger than an admiral.
 
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