Uh, this shit is pretty well defined. This isn't Boroque Works, these are the Blackbeard Pirates, poised to be one of the end antagonists in the series. Yes, I do expect every Strawhat to get a 1v1 here, this is the part where it counts. There are already parallels between certain members of Blackbeards crew vs. Luffy's, especially Shiryu and Zoro, Chopper and Doc Q, Usopp and Van Augur. The crew hasn't gotten full spotlight yet, but its extremely clear that they are built just like Luffy's in a way.
Shanks is pretty much the same way. If Mihawk partners with Shanks, he'd have 11 crew members, and there are clear parallels for several strawhat's with Shanks' crew as well.
Oda has an open love for soccer and a soccer team, which has 11 members at any given point on the field. He also has had Luffy say that he wants 10 crewmembers in chapter 2. So far he only has 9. This statement does not include himself because he specifically says nakama.
So yes, an 11th crew member is entirely warranted. Does this mean he won't stop a Jinbe or continue past an 11th member? Who knows.