Rooftop storm costs too much mana to be worth trying to be honest, especially if you consider the fact zombies usually don't cost too much mana to cast. As for the CA, I'd recommand a planeswalker such as Jace Memory adept or Tamiyo.
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Even for casual play the rule of 4 should always respected to keep the plays reasonable. At this point, it's more about respecting other players than making good decks...