We study assemblies of rodlike robots made motile through self-vibration. When confined by circular scaffolds, dilute assemblies of these rods act as a 2D gas of particles. Above a critical surface fraction, some of the bots line up in one or more tight clusters along the corral boundary while, in the bulk, gas-like behavior is retained. We find that the unified pushing of the clustered bots on the boundary can drive collective motion: by selecting corrals that are deformable but free to move, we take advantage of surface cluster formation to force the robots to work together. The deformability of the arena allows the assembly to go through narrow slits or to circumvent obstacles. Simple tasks such as pulling a load, moving through an obstacle course, or cleaning up an arena are demonstrated. Rudimentary control of these superstructures (robots+scaffold) using light is also proposed.