Official VIZ translations ;
Translator : Naoko Amemiya
''THE GREATEST SWORDSMAN IN THE WORLD''
This is not a fan-made translation, this is a professional japanese-english translation from VIZ media's One Piece volume 06.
''The World's Greatest Swordsman''
Translator : Andy Nakatani
''I will be the greatest swordsman...''
Translator : Stephen Paul
However, the same VIZ media translators uses ''STRONGEST MAN'' for Whitebeard. Which means there is a significant difference between two titles.
Onepiece wikia also uses the ''greatest'' title not the strongest.
And for Whitebeard, they are using the ''strongest'' title ;
The important difference here is, Mihawk isn't stronger than other swordsmen, which means Shanks could be still ''stronger'' than Mihawk, despite being a swordsman. Mihawk is the greatest swordsman, because he is best at swordsmanship, his title is for sword mastery, he isn't the ''strongest'' among other swordsman, he is the most skilled and greatest among the swordsman. Fujitora could be more powerful than him, by using his superior physical abilities, DF powers and Haki level, Shanks is already his superior by being ''one of the most powerful four pirates in the world''
WHY MIHAWK ISN'T ADMIRAL LEVEL - CLICK*
-Confirmed by Garp.
That's the important difference between Shanks and Mihawk. Mihawk is most skilled swordsman, Shanks is more powerful swordsman.