The Clerk would still fill out marriage certificates for non-gay couples, and gay couples could get their certificates elsewhere.
As for being arrested: Arrested, by whom?
My point up-thread was that a Court's ability to enforce compliance is dependent upon the Executive branch's resources and cooperation. I can see Obama sending in troops to enforce compliance. Would President Trump or President Cruz?
This president will send people to issue the licenses if the county doesn’t and someone or the county will be fined or go to jail. You doubt he would use his power that way?