Flying ships are not something uncommon in MMORPGs so it's not impossible.
But ships made for land, are something totally different. There can be all sorts of ships, as Joshet said, the pirate class can be more relevant. A pirate needs a ship, he doesn't care if it's on land, sea, or air.
I'm imagining something like the movie Mortal Engines
It's just in my head, and they aren't actually ships, but imagine this as a pirate city.
The other day I was thinking about a "Moving city" like a caravan moving over 1 zone as main city for Boargen, but it fits better pirates, but I was doubting and with that image now I'm convinced it can be something cool.
Definitely gonna watch that movie!