yes Aokiji is the 10th, the problem with this conclusion is that it didn't consider the time period between PH & Dressrosa arcs, in PH it wasn't known in OP world if Aokiji joined or not, but after few days it was officially known in OP world because the news spread, that's why it was first mentioned in Dressrosa that there are 10 BBP commanders, & also that's why Burgess told BB that he doesn't trust Aokiji in Dressrosa arc not in PH, not to mention that BB told Burgess that "by this logic the same applies to Shiryu", that means Aokiji situation is similar to Shiryu from BBP perspective, since they worked for WG & now they are members, so they can't be trusted because they worked for WG
BBP only spoke about the 10th commander issue in Dressrosa arc, if he officially joined during PH arc, they would have already discussed that matter before, & their conversation in Dressrosa would have not made any sense
also Kuzan's clothes doesn't mean anything, & some cover pages are not even canon unless they are in a covor story, like the one where Yamato works in parcel delivery while we still in Onigashima raid.