I have two German Shepherds and two pitbulls. One German Shepherd is a female mixed with Akita. The other one is a male. I’m not sure exactly what the other one is mixed with but his face is differrent from the other one, similar to a rottweiler. They both came from the same liter. At times I can’t tell if my two German Shephards are playing around or actually fighting. They don’t physically harm eachother though. My male blue nose pit will sniff the male German Shephard or stand by him but within a blink of a eye will jump towards him as if he was going to attack him. My female red nose pit is only 8mo old and has been mostly around my female German Shephard growing up. She does the same thing as the male pit and lounges towards the German Shepherd. My two pitbulls cannot eat together. They are really aggressive when it comes to food and other dogs. All my animals are friendly towards humans though. I love them very much and would prefer them to all get along.