How dogs behave is a result of what they have (or haven’t) learned in their environment. They always learn from us, whether we are aware of it or not, whether we want it or not. Problem behaviours are also a result of what dogs have (or haven’t) learned, and not for example a question of “leadership”.
We should focus on teaching our dogs to behave in certain situations in ways that we prefer, and that way leave out the unwanted behaviors. This is not a question of domination but simple teaching (applying positive methods). However, in all training we need to consider on the natural behaviour of dogs, and be aware of the many things that effect our dogs’ behaviour, and not demand too much of them too fast.