Exactly! I'm not a dog trainer and I don't play one on TV. I have a shelter pet who has "issues" so I read a lot. The worst situation is leashed dog and unleashed dog. Your dog wants to protect you yet has limited options. Unleashed mutt is free to move at will.
So the situation escalates with even two "best of dogs".
Best situation everybody's leashed or nobody is (secure dog park).
My mutt and I have been attached by: a rottie, loose pits (2), some kind of lab huge thing mutt .... it's scary and makes me mad. It's been fun on both ends of the leash to exorcise her demons but a lot of work. All it takes is one *&^% person too lazy to pick up a leash to undo a lot of good.
Unleashed dogs: get hit by cars, chase or get hit by cyclists, find other unleashed dogs and become a pack, get eaten by predators, "dog-napped". Mae is always leashed.
I'm sorry if this offends anyone but an untrained/unleashed dog is an unloved dog.