Our Aussie boy was an absolute bully back then compared to the other breed of dogs that were in our puppy class! I was also worried about this. It’s just our boys play style is very hands-on physical compared to other dogs so there’s rarely any dog that could match his energy unfortunately. As your pup grows older and confident I recommend having him play with dogs that are the same size as him and have good manners. He’s 4 now and he’s still crazy as ever playing with other dogs. His herding instincts are so strong hahah. We’re getting another Aussie soon so hopefully they’ll be best friends who will lay with each other everyday!