This is just a quick overview of the Humans units:
Builder: Cost = $0. Dan build and repair structures. Can replenish teammates ammo and shield them from ranged fire. Deals bonus damage to buildings.
Marksman: Cost = $0. Quick Stealthy recon class. Heavy emphasis on harassment and guerilla warfare. Strong ranged weaponry. Relatively weak in melee combat, however uses a 4 attack combo instead of 3.
Savage: Cost = $0. Frontline attack class. Almost entirely direct damage and damage support abilities. Good ranged weaponry, good melee abilities, great when used in groups.
Legionnaire: Cost = $400. Heavy assault class. Can give and take a lot of damage. Can self heal and reflect melee damage. Has very strong melee abilities and ranged weapons.
Chaplain: Cost =$0. Very efficient healer class. Can heal single targets and groups, and can also revive. Can increase damage dealt to enemies by teammates. Damage bonus vs hellbourne.
Battering Ram: Cost =$750. Close-range siege unit. Can deal massive damage to buildings. Has a limited ability to defend itself, but should be supported by teammates.
Steambuchet: Cost = $750. Long-range seige unit. Can deal heavy damage to buildings. Unable to defend itself and should be protected by teammates.