Hello, Robert here:
Actually, the SMG's is only a pistol with low value in the shootRate.
For example, if you make the pistol shootrate to .25, you will shoot 4 times per second, and you don't need to acces the code to do so.
If you want to add another weapon to the roster, you will need to add another command in the input system, but you only need to add the empty gameobject to the Weapons List in Weapon Equipment.