I think this is sometimes more a values debate than anything else - kind of like, should you spank your kids.
From what I have read, it is true, wolves are NOT pack animals. They live in
families. This makes complete sense when you think about it - you always have relatively fewer carnivores, and an ecosystem could not support an enormous band of carnivores.
Most of our research on wolves is done on artificial situations where many unrelated wolves are forced to live together in a pack.
I am thrilled to see someone else mention
Temple Grandin here, I love her.
I would like to suggest two other books I've found tremendously helpful on understanding my dog. This goes into canine body language and gives you more information than "be the pack leader" or "use positive reinforcement". I suspect that Cesar knows most of this stuff intuitively, and uses it when working with dogs, perhaps without realizing it.
http://www.amazon.com/exec/obidos/tg/detail/-/1929242352/ref=ord_cart_shr?%5Fencoding=UTF8&m=ATVPDKIKX0DER& v=glance
Amazon.com: On Talking Terms With Dogs: Calming... I am still learning a lot about training and I go back and forth on the use of force. I DO think that it is someting ONLY an experienced trainer should do, and used improperly, it can cause a lot of damage to the dog, and possibly to you. I would also say that Cesar is very old school, and that most modern trainers do not agree with his methods.
On the other hand, one of these books convinced me that your dog talks dog to you all the time. I really believe that. It's common to recommend you use certain doggy language to calm your dog, like approaching from the side and avoiding direct eye contact. That would indicate to me that dogs recognize rougher signals, such as the alpha roll, as well.
However, I think it's crucially important to make sure you know what the dog is actually saying before you assume there is a dominance problem. If there's aggression, is it dominant aggression, or fear-based? Totally different approaches are called for in that case.