story hyped Saint Shanks at peak
it didn't do any on screen justice to Mihawk
it's Saint Shanks until proven otherwise for any rational man
at least if someone wants to say Mihawk has better haki
should have the decency of saying it's a leap of faith
I have very often guessed correctly where Oda tried to bring us (I knew legendary fruit was Luffy's since the beginning and knew Luffy would pull gear 5 and awakening in Wano).
if I base my prediction of the future events based on this intuition and interpretation I have of the story, to me Saint Shanks > Mihawk but Mihawk is the better swordsman (WSS). You can be the strongest devil fruit user and still be surpassed by haki.
However, this interpretation is fallacious and that's where I join Mihawk bros. WSS means strongest among ALL SWORDSMEN and Saint Shanks is a swordsman. Haki is also part of swordsmanship. So, logically, Mihawk is the stronger one.
So in short, Mihawk should be stronger than Saint Shanks because you just don't deny WSS title and pull mental gymnastics. However, portrayal and haki link with swordsmanship have always made me doubt.
Regardless, this is less relevant than the fans make out of it. Saint Shanks and Mihawk are very close in terms of strength. Saint Shanks is the closest rival to Mihawk so it's relative. Mihawk is slightly superior than Saint Shanks but not a league above.
So, Mihawk >= Saint Shanks is the most logical thing we have at the moment.