Is that one of your core provinces where your units are now?
If yes, then it is better to lure the Swiss units out of their homeland and have them attack you. If not then it is still better to get them out of their home defense province and onto neutral territory.
Best case: you stop moving and let them attack you, so they are attacking and you are defending.
As it is now you will likely have two battle cycles each hour as each side will attack. When each side attacks the other will defend.
