These fine points of handles, mag sizes, barrel length etc are called lines of distinction. A barrel one inch shorter will probably not increase the handling and shooting capability of a gun, but it does make it illegal to own. An extra quarter inch of aerodynamics on a NASCAR will not win the race for him, but it will definitely lose the race for him. You of all people know what a pistol grip will do for the handling of that type of gun.
If you had to classify something as an “assault rifle” which in definition is a rifle that handles and shoots best in close quarter, multiple target, urban setting with armed targets (similar to what our SWAT and special ops use) how would you clarify its lines of distinction? If you wanted to legalize or outlaw it, how would you describe it? What are its outstanding features and capabilities compared to an average hunting rifle?