I'm studying animal behavior and would be interested in knowing where you've learned this information so that I can read it (the information on pack-leader training now working).
I don't mean to argue, but I have seen and heard just the opposite with dogs. A dog wants a pack leader, its in their nature. They may be domesticated, but dogs will be dogs with the same instincts as a wolf. A wolf will kill any dog that isn't a good leader and I have seen our dogs (two females struggling for dominance) try to kill one another when my mother's back was too weak to stop them. I don't know if positive reinforcement would have stopped our dogs from fighting on another or growling at us or chasing our chickens (we have seven of them and pet-sit a number as well).
I am sure that different dogs can be trained in different ways, but a large pack of dogs I don't think would behave without a strong leader.
However, I would certainly be interested to learn of any other suggestions, because of my studies I am researching all the methods and opinions of domestic animal keeping, training, handling, ect. I know that different ways work with different families, people, dogs and house-holds because they are all different.

However, I do not believe being a pack-leader is a myth.