Would make sense to have them take turns, but there would probably have to be an indicator to remind players which side is attacking first. Then again, it wouldn't solve the problem entirely, as there would still be an unfair bias within each turn, and would probably mean the cost of future strikethrough cards would be built to fit around this (e.g. strikethrough plants having an even number cost, and strikethrough zombies having an odd number cost). Then again, I think keeping the game mechanics as simple as possible is also important.