However, you were right ;)
Well, then, what prevented us from working together to achieve the correct wording?
Give the correct wording for this rule, in your opinion. How do you think this wording should sound?
I highly doubt that it's possible to give a comprehensive wording in this case. There are too many options, you can't account for everything, and questions will still arise.
And what's the point of such a ban? It doesn't eliminate "endless" battles, and it doesn't need to. But it does eliminate, for example, a very comfortable option like "harpy in a hiding spot + autobattle." It eliminates many other things, but you won't see them until you run into them.