Probably Mihawk stays the WSS, the gandhi gorosei hasn't been never underlined in that role aside from carrying a sword, also now we know he is a myth df user or something so he could be just like King and don't care for the WSS title at all, probably all he cares is to serve Im at the best of his abilities (a bit like a royal guard with Meruem in HxH).
Garland guy is the same for now also I doubt he can compete with Shanks or Mihawk, at least from what we have seen until now.