The defensive units are:

Spear fighters , Swordsmen, Archers, Heavy Cavalry* and Paladin.

  • Heavy Cavalry is like an exception as it's used as fast support - a defense of spears and swords is much better.

They are called defensive units because they have good defense skills but poor offensive ones.

  • [Calvalry] is good offensive units aswell. So see it as having your bread buttered both sides.