The guys before me have a very smart point. Disregarding Keldeo-EX countering Paralysis with Rush In, every Deck usually runs 4 Switch, occasionally 3, depending on whether or not they have other effects to make up for it, so that's plenty of time to counter against Articuno-EX, given the fast pace of this game. His high-energy cost even makes him a fragrant target for Mewtwo EX, and that's like a $6 Pokémon-EX nowadays!
Hrmm. I still wonder if there's some special way he can really get a chance...!