I took them both for a walk last night and I made the Durango sit and wait to be released before everything - walking out the door, getting into the car, getting out of the car etc. Also making sure he never walked ahead. It's a lot of work - too much to try to do with both dogs, so I am going to have to walk him separately.
My husband is gone for the week, so I have a chance for one on one time without sabotage to start laying the groundwork again.
I do use a prong collar only for walks - it's hard to do the proper correction without affecting the other dog (she ends up getting corrected too) so another reason for solo walking.
I know all about being the alpha - and I have always tried to be it with our pack - my husband has always been the omega - he has always been ranked on the bottom - none of our dogs listened to him, he is inconsistent and doesn't follow through. It was fine when we had more relaxed dogs but now with a GSD - things need to change.
I got lazy - our eldest dog (who has since passed away) was the alpha in the house and in public. She ruled and taught the other dogs (and cat) how to behave. She kept them in line constantly. I need to take back the alpha role and role of protector.
Thanks so much for the well thought out and helpful advice. You have reconfirmed what I have already known in my gut but been reluctant to face. The good news is that Durango is a GSD - he is smart and eager to learn - and I am comfortable being the leader. The hard part is consistency and figuring out how to also make sure my husband is on board.