These guys are seen a couple times in the Underground hospital in the background, though I guess they would technically include the Robot gauntlet Susan wears when she first shows up. They're the Robot Droids. They serve as the workforce backbone of the resistance. In this reality, Robot has programmed the numerous cobbled together frames so that they can act independently of his control. They usually preform menial tasks and labor too dangerous for rebels, and sometimes specialized jobs where qualified staff is lacking, like serving as a medic. Basically if I had been able to draw more of the behind the scenes of the resistance, you'd have seen a lot more of these guys around.
For their look I wanted them to look bare-bones. Materials are scarce, so they were either built from scraps of other robots or have been stripped down to their essential parts. They all have Robot faceplates though, as if they could have taken any used up robot and stick the faceplate on it.