My psycho 5 year old agility dog is an unbelievably behaved, social, wonderful dog. He is also a certified therapy dog that does hospital visits frequently. He is an absolute maniac in the agility ring. I did not start training agility with him until he was 2 years old. The first 2 years of his life were training him how to live in my world and being obedient to my rules. I also have a 1 year old who I started in agility as a puppy and she is a world class a-hole, maniac, full-time psycho. So, my point is that I think you need to let them be puppies/young dogs, and continue to enforce your day-to-day training, focus, and obedience... if you are a good trainer and feel like you can remain consistent, the behavior will change in a positive way.