I never understodd the reasoning that if you allowed an alpha dog on your bed it would create problems.
You sleep alone, therefore you are the alpha dog, right?
Well, if the dog sleeps alone, is he the alpha dog?
And if you sleep together is the dog sleeping with you and therefore becoming the alpha dog or are you sleeping with the dog, and therefore YOU are the alpha? If just doesn't make sense to me.
I've slept with my dogs for a long time and never had a problem. I've had alpha dogs in rescue a few times. Rescues don't sleep in my bed (I do not allow rescues to get too comfortable in my home because I don't know what sort of person is going to adopt them)
I've once been threatened by an alpha female Siberian, and I simply backhanded her across her face for showing teeth, and that pretty much established our heirachy after that. She never challenged me again or showed aggression with me. I know that a lot of people say you shouldn't physically hurt a dog, but in my opinion, this is short sighted. It's not something you should do lightly but it's a tool. If a dog bites me while in rescue, I'm supposed to euthanize them and I'd rather beat a dog up than kill one.
With regard to physical punishment, it's extremely important to distinguish between a dog showing aggression because of fear, and another showing aggression because of dominance. If a dog is showing aggression because of fear and you hurt them for it, it will only establish in their mind that they were right to be afraid and should have been aggressive because you were aggressive. Never hurt a dog that is showing aggression because of fear. Either don't interact with them or if you do get bitten, just grin and bear it and don't show pain or fear.