[HoneyBadger]

Well, don't forget, there will be arrows and spells raining down from the attackers' side as well-not to mention, this is designed to stop elephants, so likely, the other side is going to *have* elephants-remember, this is niche, and meant to be too expensive to be used for anything *other* than as a niche effect. If soldiers stop to destroy them, they might be slowed for a little while, but they're still destroying a very expensive, pretty fragile, hard to replace unit.
More valuable by far than the average PD unit. They're not destroying every spare bit of scrapwood on the field, like a bunch of mindless maniacs, they're destroying earth gems, and a mage's time.