Remember state preemption has very specific language in it about the things that can't be preempted. For example, a local municipality can regulate where you can shoot.

I agree with you on a consistent law. It might also be there is or was an RCW on that and the local municipality doubled up.
I'm not in favor of ANY local firearms laws.

Municipalities can basically regulate where a firearm can be discharged (cities can ban it entirely, for example, if they want to), and then they have some control over where gun stores can be located, etc. They aren't given any discretion or leeway when it comes to creating restrictions on carry.