“How do developers organize and place multiple local scripts within a game’s hierarchy—such as StarterPlayerScripts, StarterGui, etc.—so that scripts intended for specific circumstances (like area triggers or event-specific behavior) only run when needed?”
You can make a script that only connects to events, that way they can be used from anywhere that calls that event.
im talknig about local script not server one
You can still use events for local scripts.