Are they trying to establish who pack leader is between themselves or including you? If a dog is trying to establish dominance over you then training has gone wrong in one way or another. If between each other, then that will always happen. Until a couple weeks ago we had a pack of 4 (now 3). 2 males and 2 females. They always knew that the oldest male and female were lead. Now that the oldest male has passed away there is only the lead female and the remaining male has made no attempt at gaining a spot as lead. Pack mentality is not a myth. Animals no matter how domesticated they may become always have some wild instincts. I believe as long as there is no threat there is no harm in letting them establish a pack leader. It can be healthy for them to have a lead for when a human is not there. Our pack lead will lightly growl if the young male gets near the closet where the food is or if she sees him pick up one of the childrens toys. She knows the rules and enforces them even when we aren't right there to do it.