Setup question

By mu_wenbo, in 2. AGoT Rules Discussion

Me and a friend were playing and on the setup he played Black raven to make it summer and I played white raven to make it winter. How does that resolve? I said they canceled each other out but what does everyone else think?

You cannot play attachments during setup if they don't have the "Setup" keyword.

Yup. The situation can never truly happen.

Well, ****, I feel foolish. Thanks!