Man, I don't know...
I think of Roger as a swordsman, BUT Just going off from BASE Primebeard who's like >>>> to Zoro in stats, nowadays Zoro would already need like two major PUs in CoO and CoA aside from some heavy stat boosts.
That clash last chapter seemingly was a CoA clash (no sky splitting=no CoC probably) and Oden, who at the end of the chapter carved the message from Roger into the porneglyph, had the same black stripes visuals, which makes sense and probably goes to show that those are the visuals for adv. CoA. Tho Oden was wondering why their weapons do not even touch and that makes me think that this was probably adv. CoA lvl2, which Zoro, like Oden would not even have, even if/though he has mastered Enma and therefore most likely has mastered adv. CoA lvl1.
So again, two major PUs just to get near BASE Primebeard lvl and even then it's questionable if he could hang with him.
Additionally Primebeard never used his df in that flashback. And we can be sure that Roger was able to handle all out Primebeard. And guess what, there's another, a third type of haki, which is extremely rare and which we don't really know much about. And this haki color even happens to be the spec of the MC, who's actually "destined" to be on par or above that "PK" lvl EoS.
I would say it's pretty much guaranteed that adv. CoC will bring the whole game onto another lvl. And Zoro, who will most likely beat Mihawk at EoS, does not even have awakened that color yet and therefore probably will not make use of it then. And it's noteworthy that EoS might already be within the second major arc after Wano.
Additionally a guy like Oden, who was portrayed as physical specimen, who has CoC, VOAT, that kinda hype, Enma since ever (?) and was the only one who cut Kaido was..... actually treated like a child next to those guys.
And Oden is already like a high benchmark for nowadays Zoro already.
Additionally if every major dude, Primebeard and Roger included, wields a weapon that falls under the category of "swords" , why is WSS not the equivalent to WSM?
And how can things like a gravity fruit and/or homies be included into it? So much seems iffy about this title. Far too vague for my taste. It all just doesn't make much sense for me.
And that makes me think that Mihawk's title is far too "spongy" and therefore I for myself don't take it too literal.
All out Prime Roger=all out Primebeard>Non CoC Roger~Base Primebeard~EoS Zoro~Mihawk. - - > for now.