That was more than 20 years ago, so it's possible.
Oda could have changed in his mind the way for Zoro to become WSS in all these years.
P.S: Roger to Luffy is not comparable at all like Mihawk for Zoro, wth. Shanks has more than role.
Though with Shanks my belief about him being Kurohige's hypetool is there.
It would be better if both will be defeated/killed ("killed"

), since the parallels between both pairs are clear.