whether dogs in the wild or their ancestors or whatever were a pack or not the fact of the matter is our domesticated dogs live within a pack, their family. any animals who live with other animals need a structure of hierarchy to live together peacefully. anything that lives together has to have some form of leader or leaders. even a human family i.e parents at the top, kids (descending in age) below them.
there is a lot of theories, specific word being "THEORY". if it works for you and your dog, then great, if it doesn't try something else. that is why it is so important for us to be open to anything and everything that others have to say who have experience and knowledge or even intuition behind them.
i live with 3 dogs they live peacefully, never any fights. they listen to me and my mum when it counts. we are not as structured as some with out "leadership" but they know that we control everything of theirs and they are happy to follow our lead.
oh and my 2cents about the "scavenger vs hunter" i don't think any dog would starve itself because it was alone. it would do whatever it takes to survive whetehr it be hunting, scavenging or joining a group to learn from them
"In order to really enjoy a dog, one doesn't merely try to train him to be semihuman. The point of it is to open oneself to the possibility of becoming partly a dog." - Edward Hoagland