You should probably develop a list of what exactly is considered a "Spell" card. Would Nova be a spell? Immolation? What about PC like Deflagration and Steal? Then you have buffs like Plate Armor, Blessing, Momentum, etc. Even with their benefits I wonder how competitive the zombies can be if all they get is critter spam with no CC or PC cards (Bolts, Drains, Steal, Deflag, etc) and no damage mitigation abilities (Shields, AM). Taking away Steal, Deflag, and Momentum will already severely hinder their abilities to bypass any type of stall if not make it impossible altogether.