Orc warlords are usually of an elite class of Orcs. These Orcs are typically stronger than others and are trained from childhood in the art of war and hand to hand combat. If Orcs were not so inherently lazy, it has been suggested that perhaps all Orcs could be as powerful as the Warlord. Thankfully for the world's sake, Orcs show no sign of becoming motivated anytime soon.
Once deemed ready for battle by their masters, Warlords are given a heavy suit of armor and sent to decimate the enemy's ranks. With their huge two-handed swords, they can take on any opponent in a melee and execute a number of maneuvers to defeat their foes. Even when severely outnumbered, Orc warlords can execute the round attack, swinging their great blade in a wide arc in an attempt to cut down many opponents in a single swing.
Warlords are one of the most powerful Level 3 units in the game. Their high, well-balanced stats and ability to use round attack make for a force to be reckoned with, especially in large numbers. A Warlord will pay for its upkeep cost far more efficiently than lower Level units, so Orc cities with upgrade level 3 should be producing them almost exclusively in most situations.
Although the Warlord is unmatched in close combat with all but some Level 4 units and possibly Titans, they are at a disadvantage when greatly outnumbered by ranged units due to their average movement speed. They also have no answer to flying units with ranged attacks, so mustering an army of only Warlords when your enemy may have those types of units at their disposal is a bad idea.
Warlords make for excellent defenders to fortify a location and deter enemy raids, since there are few units or armies that would risk the losses of going up against one or more of them. They would need to be paired with Rams or Catapults to raid cities, lacking a way to scale or batter down walls themselves.