Main units can change their weapon and item configuration at the loadout screen. You can choose from everything the com has researched. Note that you cant equip more then 3 items and that you cant have more then 1 weapon.
Starting main unit. Free. Starts with 250 hp.
Scavengers are the first unit available to the Beast Horde and like the Human Nomad, are free. Although they are not as strong and resilient as other units they are quite effective in early game play. These are not the ideal units to use when going after enemy buildings or siege as their modifier is moderately lower than their base damage output. Their real power lies in their ability to hurt non-siege units.
Tier 2 main unit. Costs 2500 gold. Starts with 400 hp.
Stalkers become available when your commander has completed the stalker research which becomes avaible when the lair reaches level 2. They are significantly stronger and more powerful than the Scavenger. If you plan on taking down buildings early, a Stalker is a great choice with a 50% damage modifier over and above their base damage rate. For their cost/damage ratio, they also have the advantage in straight melee damage over other non-siege beast units having a 20% higher unit pierce modifier over the more powerful Predator. They do the most melee damage of all the main beast units. Simular to the Savage, who does the most melee damage of all the main human units.
Tier 3 main unit. Costs 4500 gold. Starts with 550 hp.
These critters are hell on two clawed feet. One swipe from a Predator will just about kill a Nomad and two swipes will kill a lower level Stalker. A level 6+ Predator can sustain 2 direct hits from a marksman bow to give you some indication of their strength. This is why humans rarely research the marksmanbow. You can use this unit for just about anything, but at 4500 gold and any accompanying items you might want to use with it, the price tag for a fully loaded Predator can be steep. Hope for a very rich commander or make sure you are picking up any loot you earn to keep putting these on the field. Kill npc for gold. They give gold and a melee orientated predator should have no problems with most of them. A predator has enough with rabid or carnivournious for keeping most enemies away from base. Legionnaires are more expensive to field.
Note: The shaman cannot change his item configuration. He can have up to 3 items/tools. If the commander has researched them, the shaman spawns with them. He cannot choose which ones to equip or unequip.
Healer/support unit. Costs 1500. Starts with 250 hp. Has a melee attack, that can be used for repairing, mining and hitting enemies. His melee is the only attack he has. The first item is for healing allies. Shoot at wounded units, damaged siege units or damaged buildings to restore some of their health. The second item is the resurrect. You can only ressurect main units and other shamans. You can only resurrect people if they didn't go to the load screen yet. These people are marked with a skull on the map and have a red cross hovering above them. The third item is the shield ray. Use it on allied units or buildings that are under attack. It decreases the damage received by 60%. Only one ray can have effect on each individual target at any time. The shield effect does not stack.
Their main goal is to damage enemy buildings. Protect these with support units.
note: there is no tier 1 siege unit, siege units are not researchable till Tier 2.
Tier 2 siege unit. Costs 4000. Starts with 330 hp. Has no melee attack. Shoots bolts of magic that can kill nearly any enemy unit (except siege units) with one hit. (It can be blocked). Kills unshielded guard towers in two hits. Summoners have infinite ammo, because their mana regenerates pretty quickly. You need full mana to shoot and each shot takes all your mana.
Tier 3 siege unit. Costs 7500. Starts with 4250 hp. The only siege unit with a melee attack, but however has no ranged attack. Enemy legionnaires can survive a direct hit from a behemoth, but that's not easy. Kills unshielded guard towers in one hit. Behemoths have infinite ammo too, since their attack does not require ammo.
Note: At lvl 10, every unit has 70 extra hp.