When I used to have Belle and Maggie out together, they would be more like a 'pack' in behavior...they would gang up on a strange dog or be friends with it, but would agree together on which behavior it would be; they would herd/hunt/chase a strange cat, rabbit, bird, etc, at least they would try, since I kept control of the leashes). If I took either one out by herself or when they were inside, they acted more individual and we could see that Belle was nearly always the dominant. Our cats were also part of the 'pack' as far as the dogs were concerned (and the cats had higher pack status than the dogs). I don't know how they knew which cats were allowed and which weren't, but they would only bark at the strays and not ours when viewed through the glass door. Now that I only have Belle (Maggie stayed with my ex when we separated), I try to get her to a group class situation as much as I can so that she stays socialized, so her behavior there is more like the individual behavior she used to have, focused more on me than the other dogs (finally!).