Constructors and Cerebrate

Constructor: Essentially "field medics" who are much more than happy than to swarm the frontlines and fix everything they can get thier claws on, or if its too damaged to be repaired, salvage it to build a new machine out of the scrap!

Cerebrate: taking the role of field generals, they dont have much in the way of armor, but their gift of free will (and encyclopedic knowledge of warfare) they become deadlier and deadlier with every passing battle, all Cerebrates in active service will constantly message eachother on weaknesses in the enemy, or thier own ranks. But this tends to make them bullet magnets once thier purpose is dicovered by the enemy...