As long as you are seeing improvements and not seeing the display you are moving along at just the right pace. The dog determines the pace of these exercises. Again successful then work towards four and so on. Stranger approaches within 7 feet and tosses one piece of steak towards the dog and leaves. Stranger gradually gets closer and closer.
Stranger crouches down.
Or sits tossing some food on the floor near them. The stranger is not looking at nor talking to the dog. If you are moving at a nice comfortable pace for the dog he will begin to look at minimum not concerned and possible actively looking forward to this person appearing. At no time should the stranger reach for the dog, eventually the stranger can hold their hand below the neck level of the dog and see if the dog wants to make contact. Move to where the dog take a treat from the strangers hand.