While talking about this, it probably is balanced, but I think the zephyr dragon actually does less than ideal damage, it is meant to be the least damage sure but I feel like it doesn't do enough damage still, I dunno....
Yeah but it makes up for it with the highest health. It can afford to stay in the thick of it buffing troops and supporting with spells while the mountain dragon (which has the lowest health) can really only appear for short times as it's very fragile to compensate for it's higher damage.