This is a good move, I had already came up with the idea in 2016 when the LOC was flaring up, raising a separate 'western army' ie an enlarged FC with its own armour ( old Ty59 or Al Z ) and if budget allows half decent Air defence ( not counting manpads in that , they should be mandatory in any formation ) and surveillance drones and helis,
What this would do is offer a specialized army for the West with locals pashtuns balochis so less ethnic tensions , be cheaper to raise and maintain than normal PA units , officers can be posted to these for limited times so they get mountain experience and more diverse terrain experience, it will the leave the PA for its main task of countering the eastern hordes and when one day peace is achieved in the West or puppet gov is established in Afghanistan, these battle hardened units can be shifted to eastern regions with mountains etc
Also I forgot FC formations already have their own SOG too