I totally disagree with you guys on the cats. The harder the defender, the more important they become. A knight costs twice what a cat does, and a grenadier costs 2.5 times as much. And the cats will cause considerable damage attacking the enemy city, not necessarily to the primary defender, but quite a bit to the others. I'd much rather lose 2 cats, fresh out of the assembly line, than my CR3 mace, who only has a 54% chance of winning. If the city only has 2-3 defenders, sure the suicide cats aren't as useful, but outside of pathetic tundra and desert cities, I suspect we'll see more than that in most cities.