Mihawk > Roger
When Roger tried to target Whitebeard and his YC1 got in his way
YC1 got neg diffed.
When Mihawk tried to target Whitebeard and his YC3 got in his way
Mihawk's attack got neg diffed.
When Roger tried to target Whitebeard and his YC1 got in his way
YC1 got neg diffed.
When Mihawk tried to target Whitebeard and his YC3 got in his way
Mihawk's attack got neg diffed.
First of all, why is Oden a "YC1" and Jozu a "YC3"? Jozu is clearly the #2 of the WB Pirates in Marineford, and if you want to go by division numbers (which Oda stated is wrong), Oden is #2. Whitebeard was NOT a Yonko at the time, and the commanders of that time had much higher potential. Oden was not comparable to "YC1s".
Second of all, Roger was using a named attack, Mihawk wasn't.
Lastly, an air slash has 2 components: cutting and power, which is a perfect match for Jozu. His diamond durability allows him to cancel out the cutting part, and his physical strength allows him to nullify the power behind it. Just because Oden > Jozu, it doesn't mean he would have fared better.