If you have this opinion, the whole story is against you
First, Roger was alive at that time and the strongest man in the world could not defeat him..mihawk>roger?
This is almost impossible
Second, Mihawk was looking for a stronger opponent than Shanks..So we have to conclude that Roger is weaker than Shanks
The third Mihawk was at his peak and probably less advanced in his goal than the current Shanks..While Shanks admits that he received a wound from bb during that time..Can't Shanks kill bb with advcoc?