I know all that, I read the same manga than you do and I also read the SBS.
If you read my message properly, I perfectly mentioned in it that if we only talk in terms of WSS (which is valid to be used as the only argument atm), of course that Mihawk is stronger than Shanks. My concern was about if that was it since all swordsmen are not portrayed the same manner by Oda. I would be more confident in accepting that Mihawk > Shanks if Oda could provide more info on the WSS title and on Roger, it's a valid concern and you don't have the right to criticize it just because you accept this statement more easily than I do.