A familiar exercise in sport protection events is the Bark and Hold. A dog is sent to “find” a “hidden” bad guy behind a blind. The dog “finds” him, starts barking and so long as the man doesn’t move, the dog is “holding” him there.
There is no practical use for this exercise. First, if a dog finds a bad guy in your home, and if the dog just barks and doesn’t bite if the man doesn’t move… it would be simple for the man to slowly pull out a weapon and eliminate the dog. Now the dog is eliminated by the criminal, and the threat remains.
Further, breeders for dogs like this will select dogs that “leak” like this, bark way too easily when stimulated. Who wants a protection dog that is easily stimulated to bark when they encounter a threat? There is a difference between a hunting hound that barks when it trees a raccoon, and a protection dog that yaks too much and too easily.
As a matter of experience, since I work with pet dogs, I do not teach dogs, like German Shepherd Dogs, to bark their heads off whenever the doorbell rings, someone walks past the front of the house, and such. None of those are representative of a real threat. I prefer a dog to naturally bark, not something that is artificially created through training or breeding. Most of my students that have these types of dogs note that their dogs rarely bark, that is if we started out the dog correctly as a young puppy and they didn’t buy a dog that was bred to bark at the drop of a hat.
I think a bark should indicate something meaningful that I should be checking out. Not a lot of nuisance noise that has no useful purpose. If my dog barks, or growls, then I will go check it out. If I had a dog that barked at everything, then eventually you stop checking out situations that might actually be relevant to your safety.
Plan accordingly.