Having done Attack training with various dogs in the past, that is only one of the ways to control. If the dog is really aggressive, you have to exert dominance over him or it's your ass. The moment you turn your back he will attack you if you're totally unprepared for it. You can let on like you're unawares and invite the action so that you can throttle him to submission without killing him. The other way is through kindness which only works with dogs who haven't been mishandled before they got to you. You have to use both methods at the same time to keep the dog(s) on a even keel. Once dominance is achieved, trust is established by kindness and being gentle with him. After that, they will love you to death and God help the poor dummy who shouldn't be in there with 'em.