This is more of a general question and not so much about a specific technical issue. This is more like a question about approach and concept.
I just purchased a Top Down Shooter controller off of the Asset Store and it's made with PlayMaker. The package includes an animated (Mecanim) model with a pistol. It shoots and kills enemies and there is a camera rig that follows it. It all works well and seems like a great starting point.
Seeing that the only weapon supported by this controller is a Pistol, I want to add support for a Rifle and Melee mode. So my approach would be to copy the Pistol FSM and create two other versions for the Rifle and Melee, then adjust accordingly ie. use appropriate animations, firing rate, ammo etc.
These FSM would then be activated if the player acquires the corresponding weapon (the melee FSM being the default running FSM).
Anyway, I hope this "question" makes sense as I know it's quite broad. I just wanted to get opinions if this is the right approach or if there might be better solutions.