Well, you have big dogs with really stong muscles in their necks....so to be quite honest, I really doubt the prong collar actually hurts them unless you are being abusive, which I know you are not. Maybe start with that, if that is working for you, and then "down grade" to a different collar. The majority of people out there, are not looking to hurt their dogs, they just hear "stuff" and read "stuff" and think that's the answer...I am not directly saying this to you, but just to people in general. I take my training very seriously, it's like an art to me. Bonding with the animal and having them doing things that they like to do. Using pos. reinforcement.... I am not good at much, but animals are really the only thing I am great at.
I don't recommend using a prong collar on a yorkie...but a rott, is a different story.
This may and will sound like bragging,,,, but I could do wonders with a dog in several minutes not using that type of collar. THEN AGAIN....I have been trained to do this, it's my life. I can't balance a check book for the life of me, but I can train.
Rottie, if this is working for you, and your dog is not hurting, keep going if you are getting positive results and then move forward by using less restraint.