The details of dog breeds and the details of training are not my area of expertise, but I'll check with some experienced K-9 trainers and see if I can get any further insights.
From personal experience, I agree with the idea of reinforcing desired behavior and discouraging/scolding the behavior you don't want. However, the key to that is knowing the difference. I have a female half Shepherd/half Chow. She's a great dog that we chose for her mild temperament when my daughter was small. Although she's very mellow and quiet, when someone approaches the door she goes ballistic and the hair on her back goes up in a very aggressive "stripe." Although it's sometimes annoying that she does this--especially when you know who's coming to the door--we NEVER discourage it. Instead we praise and reward it.
Conversely, when she's staring out the back window barking at the squirrel on the fence, we tell her to be quiet. However, we only do that when we KNOW that it's a squirrel and not an intruder in the back yard. When she complies and shuts up, we praise that too.
She's not the smartest dog in the world, but we've managed to teach her the difference between what we consider good and bad reasons to bark and posture. We also continue to reinforce that behavior with praise and treats.
One thing we NEVER do is tell strangers that "she's a sweet dog, don't worry." First, we don't open the door for strangers and let the dog barking do most of the deterrent work. If it's a delivery we're expecting, like a pizza or Fedex, I keep her right beside me and let her growl. I'm sure she considers anything in a UPS or Fedex uniform a food group, and I'm fine with them thinking that.
I hope this helps.
Stay safe,
Mike