Não
Olhando para a entrada de passo de 5 pés no PRD responde isso:
You can only take a 5-foot-step if your movement isn't hampered by difficult terrain or darkness. Any creature with a speed of 5 feet or less can't take a 5-foot step, since moving even 5 feet requires a move action for such a slow creature.
Então não, eles não podem.