To be honest, the whole pack structure thing is totally over done. In fact, dogs don't actually have a linear pack structure like most people believe and will simply defend resources based on how valuable they think they are, and how insecure they feel about losing that resource. Having said that it is so so important to be consistent. If your dog isn't allowed on the couch then he isn't allowed on the couch. Changing the rules does get them confused and therefore anxious, especially if they get in trouble when they 'break' a rule, because the rules have changed. HTH.