The Wildmen come from Dunland with their clubs to fight for Isengard. They are a very weak unit but are quite cheap. They can be recruited from the Clan Steading settlement expansion along with Wildmen Axe Throwers and Wulfgar.
The Wildmen of Dunland have access to the following upgrades:
Banner Carrier - This upgrade can only be given to a level 1 battalion and will promote it to level 2. At level 2 the battalion can regenerate units when out of combat. Cost: 200
Heavy Armor - Increases the armor, hit points and damage resistance of the unit to ranged damage. Changes the unit's armor set to EdainInfantryHeavyArmor. Cost: 300
Torches - This upgrade increases the damage of the Wildmen towards units and buildings. Cost: 200
The Heavy Armor upgrade can only be given to the Wildmen of Dunland through Wulfgar's level 10 ability, Arm.
The Wildmen of Dunland are among Isengard's tier-1 forces. They are among the cheapest soldier battalions in the game, and come in decently-sized droves, which make them much easier to mass-produce than Uruk Scouts or heavy Uruk-hai. At the same time however, they are quite weak, and their strength is more in numbers than in health and damage. The Wildmen should be used to raid enemy settlement structures to make good use of their Pillage ability, and occasionally combined with uruk soldiers to shield them from harm for a while and to swarm the enemy with number superiority, much like how Mordor swarms enemy forces with a lot of orcs. While they are cheap and can earn you some resources back by pillaging enemy buildings, they aren't too useful as soldiers until you have Wulfgar available to give them heavy armor, as well as the proper upgrades applied to them such as burning torches and banner carriers. It is important to pair them with Wildmen Axe Throwers and Isengard's uruk warriors, so that they can last a little bit longer on the battlefield. While it is possible to swarm opponents with wildmen in the early or middle game, they're not something you should rely on, even for their numbers and resource-production powers. Isengard's main focus is more on their heavy infantry divisions with full upgrades and numerous siege weapons.