Does anyone ever use them?

I'm playing my first campaign where I'm trying out the arrow catapults, but so far it seems that these visually cool weapons simply don't kill enough to justify their huge upkeep costs.

Although there was one exception - during a bridge battle placing the catapult directly in front of the bridge and having the lowliest skirmishers flanking both sides made for the most hilarious slaughter of the AI I've ever seen...

But in general, I find they'll rarely kill more than 100 units per battle, which is alright, but not really worth the thousands of mnai I'm paying to keep them.