Not cropping their ears is fine if you do not show your dogs and you one have one.
I have cropped ever since we had more than one bully in the house. A couple years ago when we got a second one we wound up having to crop her ears because when they were playing her ear got split. I am not talking just the tip either, it was almost to the base of her skull. She never whined when it happened and it was only the blood that led us to a problem. They do play really rough so I now deem it necessary to be cropped in our house.