Here's a bit of my experience, although it doesn't have to do with males, it does deal with same sex relationships. We just introduced a female Neo to our "pack" of all females...2 mini-schnauzers and a Ridgeback mix. I was worried about dominance issues because one of my minis is a bossy B! It's hilarious because Olive, our Neo and Aurora, our bossy Mini Schnauzer do go at it from time to time, but they've become wild playmates. Olive definitely wants to be the boss, but Aurora won't let her. Aurora is NOT intimidated by her size. Aurora weighs about 11 lbs and Olive is about 140. I was told a long time ago that when you have a bunch of female dogs in a household that they see the female human as the female Alpha. I see that now. They all see me as the boss, but respect my husband in a different way. They also see my daughters as part of the pack, they respect them as being higher up on the chain and treat my husband as the main Alpha. It's really interesting to see. I also think socialization is key. All of my dogs have been socialized with people and other animals from the beginning, even our new girl, Olive. Her former Mom took her everywhere, has a successful business at home and Olive hung out in her office, around everyone who came and went. Sometimes "play" can get a bit scary because Olive's mouth could swallow my minis, but she knows when to back off. It also helps that the minis can run circles around her and get away if they need to. I won't lie, I do worry sometimes because I've seen a couple instances of play turning into aggression, but it settled down once Olive and Aurora found their places. I agree with what someone else said, it's a chance you have to take. I had a male Malamute who was about 130 lbs and he was the most loving, non-aggressive animal I've ever known. I had him from puppyhood until his passing and he welcomed every living thing with lots of kisses and play. New neighbors would warn their kids to stay away from the "mean snow dog" which was kind of good, it kept the rif-raf away, lol. He never had any problems with any animal, regardless of sex. I used to take in strays and foster until we could find them homes and I even had male pits at times. No issues. I think it all has to do with the personality of the dog, your attitude and ability to lead and train. Trust me, I'm no expert in training or anything, most of it came from experience and Bear, my Mal, helped me learn.