The Non-Combatant units haven't been designed for combat. They exert no Martial Law, have no <l:6,136>Zone of Control<e>, can't <l:6,23>pirate<e>, <l:6,22>pillage<e> nor <l:6,24>reform cities<e>, are <l:6,112>Special Forces<e>, and cannot expel units but can be expelled themselves. The Non-Combatant description includes all of the above features, so they are omitted from the text. Note that some of these units can still assault, but they're usually poor fighters, and even those can't capture cities.