Quite simple, really. If the NG tires don't have enough traction, merely move all the SLF as far forward as possible, standing up, as needed.
Has an independent body studied the efficiency of powering a motor on the nosegear by a generator on an APU, vs. air propulsion from a wing mounted engine? Each power conversion, from air pressure in the APU spinning the generator that converts mechanical energy to electrical, then converting electrical energy to mechanical to turn the nose wheel has losses.
GB