blackbeard has 10 titanic captains. Therefore, it makes sense for SHs to be 11 as well, unless the 10th titanic captain is the one who’ll betray blackbeard (the only ones that make sense in this case are Gecko Moria and Aokiji). The 11th crew member on the other hand should be someone we already know that has already created strong bonds with the crew; the only one is Vivi, but she’s not strong enough. That’s why i do expect that she’ll get a power-up in the upcoming chapters