I sincerely think Mihawk is meant to be fought with Shanks group, WSS or not. Consider every other group, all of their assumed #2's are Swordsmen to some degree. Then you have Beckman. CG evidently does not have manpower to do anything outside of Mihawk, even if they recruit other Shichibukai, its just a bunch of former Luffy villains at that point.
At this point, Zoro can fight Fuji after Mihawk, but that also doesnt mean Shanks and Mihawk have to lose before Akainu/Fuji. Just my opinion on this, because Mihawk really doesnt fot anywhere else.