I was more so talking about those leather outfits
Shilliew and King both bought their jackets from the same manufacturer, it's really obvious. Loki's outfit is more Viking style, and we couldn't see much of his upper part because of the chains.
Other wearing Leather?
Well, all the Beasts Pirates have this leather style of theirs,
Katakuri has leather pants a bit similar to King's,
and I think Robin once had a leather outfit somewhere, if that counts.
That's all I can think of right now.