We have always had a pack situation here. We allow our senior dogs to assert dominance, actually, we encourage it. Once dominance is asserted the relationship is peaceful. I have actually at times "helped" the senior dogs get dominance by discouraging the young dog from fighting back and allowing the senior to "give it to him". No puppies were harmed during the interaction. My two pups are huge compared to the Chihuahua male, but they 100% respect him.
That being said, I am physically able to do what I just described. The bigger pups know that I will back the senior Chihuahua if there is ever a scuffle between them and they seem to be okay with that. The pups are both completely and willingly submissive to us, they don't cower in our presence either. I am an advocate of keeping the natural confidence in a dog and am even training them to use the natural confidence each one possesses to their and my advantage. I want my pups to come to me confidently and expectantly at all times.
I have watched dogs and wolves in pack situations on how the dominant ones relate to the rest and have to some extent copied that behavior. I am however, friendlier to my pups than how they would be treated in a wolf pack environment. I believe in fair treatment and respect toward my pups. Respect as in allowing them to make mistakes and not aggressively scolding them. I do scold them at times, but not to the extent that they'll cower in my presence. I have excellent recall with them, just using my voice to guide them. They are currently eight and a half months old and seldom need to be leash controlled.
They experience a lot of praise and very little scolding.
Note: I have read and watched videos on puppy/dog training so I'm not going at this willy nilly and from the seat of my pants.
Again, I am able to physically enforce everything I have written here and have extensively worked at it since they were ten weeks old.