Infantry
All infantry except Commandos and Engineers form a squad to boost their efficiency. Also all Infantry can garrison structures except the Zone Trooper.
Riflemen squad
These guys do good damage and can garrison structures. Also can build a sandbag bunker.
Missile Squad
These guys are best against tanks but also garrisons structures like all infantry.
Engineer
This guy can steal structures from the enemy but also can repair them.
Grenadier Squad
This group of infantry are strong against most foes but tanks and Nod Venoms are a trouble to it.
Sniper Team
The two infantry that call for artillery barrages and kill any infantry in one hit.
Zone Trooper
These heavy infantry are a danger to all ground units.
Commando
The GDI commando can jump jet and bomb structures but also are good heavy infantry slayers.
Pitbull
The fastest GDI ground unit. Sucks against Infantry but good against air units and detects stealth. Also this vehicle can be outfitted with a Mortar.
APC
The armoured vehicle can carry infantry but infantry can fire even when inside the thing. The APC got gattling guns for air and infantry.
Predator Tank
GDI Medium Tanks that are used against Light Tanks but Nod Avatars can reduce it into a scrap unless swarmed.
Juggernaut
Artillery that must be dealt with by Commandos or Aircraft as for the cannons work against all ground foes. Known for friendly fire.
Rig
Unarmed vehicles that deploys into Battle Bases. The Battle Base is a heavy defense platform that can also repair friends in range and detect enemy Stealth units. It however hates the Nod Black Hand which got powerful armour that wear capes and flamethrowers.
MCV
This vehicle is the founder off all Bases. Weak armoured unlike in the other games.
Orca Gunship
Fires at ground foes and detects stealth.
Firehawk
Fighter and a bomber that is useful alot of times.
Mammoth Tank
This big beast loves its 150 cannons and its versatility but cant autoheal itself ever again.