I had a dog in the past that was like that, I thought it was just unique to him. I got him as a rescue, a newly altered 5 year old. He had been used for breeding and was quite handsome.
He walked well on a leash with me and when we'd run into other walkers with dogs, there would inevitably be some smaller dog that thought it's job was to bark at him. At that time my dog was a very muscular 90 pounds.
I never saw what he did, but it happened a lot. The other dog would suddenly mellow out, like in mid-yap. My dog never moved.
I used to think as a breeder, he was probably around a lot of puppies and developed his mojo as a survival skill.
Very cool how your dog takes on that role of peace keeper!