Have they mentioned the 10th or did they just say a number I can't remember? The wikia mentions Jesus, Laffite, Shiliew, Van Auger, Q, Sanjuan Wolf, Vasco, Catarina and Pizzalo. Kuzan would make 10. Who is the 10th you are referring to? Nevermind I found the pageBB has 10 commanders. That means someone joined them during the TS.
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It says 10 giant captains but no new name has been given to BB Pirates other than Aokiji so until a character is introduced it's implied Aokiji is that 10th captain.
Tbh I'm not even sure what you were trying to point out, I said BB had 10 commanders not counting the horse. They are as far as we know Jesus, Laffite, Shiliew, Van Auger, Q, Sanjuan Wolf, Vasco, Catarina, Pizzalo and Aokiji until proven otherwise. Saying there's another new BB Pirate aside from Aokiji is nothign more than you projecting.