
I much prefer the "Halti" it leads from under the chin and not too far back under the neck. The head turns easily with a Halti and the dog is kept nearer and not so far in front.
A Halti fits more like a Headcollar than any other similar design. A good fitting headcollar can lead a large horse or cow but ot would never work if the lead point was too far back under the chin as many of the head slips do.
A well trained dog should walk at heel on a loose lead, there is no need for him to walk a dogs length in front or pull.
It looks as though your friend might have her hands full if this chap has learnt bad habbits whilst out on the lead, I hope she gets on top of the problem fairly quickly.
(dont even think of a harness, after all horses, donkeys and sled dogs are trained to pull in a harness although designed slightly differently! )
Good luck.