Hi again,
Certainly, when your dog is feeling insecure and unsure of what action to take then his natural instinct is to look to the pack leader for direction. When a stranger enters your area your dog is checking out what he should do by what you do and gaining security and reassurance by the contact.
Excuse my ignorance, but I have never heard the term "role playing" applied to dogs before. Could you help me out a bit and explain it for me?