I worked on a Pac-Man-like game based on the Strawberry Shortcake characters. 4 directions all in one Spine file and skins for 5 characters. Not many animations between all the characters though but it wouldn't be hard to add more without crying(much).
The way we had it set up was to have a North bone that would become the "root" of the North facing character with a skeleton for the North facing animations built off of that. Then, of course, the same setup for each other direction. This way in Setup we could pull the North's "root" bone away from the others and see only the North facing bones and images when animating. Then when all the North animations were completed we just return the North's "root" back to center.
Animations were organised by direction so N-AnimName, and S-AnimName, etc. Because of the skeleton tree was organised with a single bone as a root for each direction setting the other directions views to invisible when a North facing animation was playing was pretty simple.
I don't know if any of that would help but in the end the skeleton looked like a godawful nightmare when everything was centered, but digging into it it's not that bad.
Good luck!