@Glennn,
The issue isn't whether a pistol grip increases or decreases the deadliness of a firearm. All firearms are deadly.
The issue is whether a pistol grip is or is not a necessary item to a firearm to consider it a component versus an add-on product that is not essential to render a firearm useless without it. Therefore a pistol grip can be excluded from Strict Scrutiny and not applicable to the 2nd Amendment.