I am in no way being critical of your training. I'm just pointing out the different philosophies people have in training. You said this dog is from van Leeuwen lines, which are dryer meaning they don't have crazy drive for a toy, but have strong, forward aggression as adults. I know that **** van Leeuwen would never use a toy and wouldn't even start training a dog until he was somewhat mature. This is what works for him. I'm more in line with starting pups early because I think you can teach them how to learn at a very early age which has advantages, as long as they are taught correctly. It is similar to research that shows children can learn a new language much easier than an adult.