At this point I think Oda is just trolling with giving these new characters swords in their introduction.
Just look at Greenbull, he was introduced with a sword, but only uses his devil while fighting, so definitely no swordsman.
If he really introduces a new high level swordsman he should just give their swordsman rank, that would also give us a feeling how they stack up against Zoro and Mihawk. I think he should have done this from the start, that would have made Zoro's journey much more tangible, now it's just defeat Mihawk and done.