It would be awesome if you could provide 3-4 different states for your windmill so that it could be easily animated. It would turn your tiles alive. Amazing set by the way! Nothing comes close to it in the Asset stores
I've actually got almost what you ask for on hand. Check these out:
With these, it's possible to draw the vanes overtop of the windmill then rotate / angle the vanes via code. Not a frame animation, but it should be able to do what you ask. Does that help?
