Not sure for those you “build” but the Mutog you buy is a worm mass killer.
It eats worms in one attack (despite worms have higher Hp), and gain 2AP. It is a bit difficult to move but it can chain kill worms. Ain’t that cool?
He is ok as cannon fooder but two vehicles are much better for that.
You can try make it kill stuff so it heals too and benefits of the 2AP but its attacks are too low damages so it’s hard.
Still experimenting around. There should be something Priest, but nothing obvious.