Cave knights a bit too powerfull?!

[K]

Like any high protection/high HP unit, the counter is magic and AP or AN damage. The computer rarely has the ability to get these things, but humans race for them.

Still, its a nice unit....they just can't kill things very well. Throw in high damage units, and they can just keep beating on the Drakes until they die (don't forget that as a unit fatigues out, they get a chance to be hit with half protection).