They're the lowest level social class, they work and work and they're harmless.

They're sent to battles as a distraction, they can sport military or scientific specialization, but it doesn't matter to you.

You should just destroy them as you please/need.

Weakness: everything

They're mindless fanatic lunatics, they'll charge you at full speed, self destroying to damage you, the leaders have no respect for them and they're sent in relentless assault waves in every clash.

They're easy to kill but mind the powerful close range attack, it can be interrupted destroying them. If they overrun you it's the end.

Weakness: everything

Low level soldiers and highly lazy, they're usually tasked with guarding high ground leveraging their mortar, drones, airburst shots and missiles, chosen depending on your actions.

They hate close combat and getting hurt, they'll run when The Reaper comes close or they're damaged, trying to self repair.

Their low height can make them hard to hit from above.

Weakness: everything at close range, Hunter and Cannon from afar

Barely sentient they're teleported to the field just to seek and destroy.

They pack a punch exploding, so it's better to prioritize dodging when they're deployed, using grab boost, jumping or dashing.

Once diving their aiming capability is strongly reduced.

Weakness: Hunter and Dolphin

It's the first ranked soldier you meet, they're self confident and heavily armored, they're rude trouble-makers that meet at the pub when the shift is over.

They alternate two main attacks: the missile launcher and the cannon: the first should be dodged, while the latter should be dodged when the aiming cone  shrinks. Watch the feet! From close range they blast an electric overcharge over the terrain, high mobility is adviced.

Weakness: can't aim fast targets

When the robots' matrix is created at the factories they're immediately selected based on their characteristics, Shooters are chosen among the best of the worst, yet they feel elitish and professional. Their equipment is still pretty basic.

They keep shooting and scooting around you, alternating different patterns of attack, they're generally low priority target, but never stop moving or they'll destroy you in a second.

Weakness: Cannon and grab

They're kind of a middle ground in the army, nobody really likes them, but they don't care because they're dumb as a brick, and while fighting they clearly display that.

They just stand there covering with the shields when you shoot them, or launch a grenade in front and, having no close weapon, they just cover up when you're close, not taking care that you can destroy their shield with one hammer blow.
Also you can destroy it using Puller, which combines well with melee.

Weakness: their rotation is slow and past the shield they're fragile

They're feared and respected, their fit and well trained, capable opponents at all ranges, from afar their impenetrable shield protects them when you aim and when they stop covering they charge you like lunatics with a powerful spear, jumping and hitting.

They're not invincible though, they can be slowed and they can overheat exposing their weakspot when they take damages, giving a short chance for a critical hit.

Weakness: CQC grenades, can be hit at short ranges, if you're brave and fast.

Another elite, ranked unit, they're so fast and their reflexes are perfect, they can dodge most shots and even keep off of sight when you look at them, moreover their ranged attacks are implacable and long ranged, which pairs well with their love for keeping the distances.
Slowing has limited effect.

Weakness: dodging multiple grenades is limited, puller can bring you close, Dolphin's istant attack can partially negate their speed