I have a 7 year old female (spayed) English Bulldog, a 4 year old male (intact) Tosa, and 2 year old female (intact) Tosa. I run what I call a "flat pack" structure. Nobody is allowed to express any dominance over the other, I'm the only boss. For example, if my Bulldog is chewing a bone, the Tosas aren't allowed to take it from her. They get along great, and I don't crate or kennel any of my dogs. I do have to watch the two females when play gets heated, they can squabble sometimes, but nothing that a good yell wouldn't fix. They are all fed side by side, and my female Tosa is the only one that has displayed food aggression (a mild case). So, I never leave the kitchen at mealtime. When I'm not home, i don't think anyone moves, and so far I haven't had any issues.