No?
Sanji has his Martial arts and Haki. And now, his Germa augmentations.
And even then, Sanji is someone we've actually seen fight. Saint Shanks not so much. Wait till he fights at least once lol.
Idc lol. If all Saint Shanks has is a fire Sword, then Mihawk is in trouble. You telling me Mihawk couldn't beat someone with a little fire on a sword?