This seems too complex, too prone to failure, and too difficult to keep powered. I imagine the first industrially viable modular robots will be solid-state, wit

This seems too complex, too prone to failure, and too difficult to keep powered. I imagine the first industrially viable modular robots will be solid-state, with a mains power supply which is able to connect ambiently or arbitrarily. Power distribution circuits will be dynamic, and the abundant power will be used to control multiple electromagnets per module.