G1 if they have both online and are on the play, which represents something like 15-20% of openings of 2% of matchups in 1/3 of games, you will have to Living Wish for both Knight/Pridemage and Emrakul and cycle both in in order to GSZ. Postboard you simply board in one of them as a GSZ target. It's definitely not worth switching to a monogreen creature simply to address that very rare scenario unless your meta is flooded with Dragon Stompy.