I never did get Hogan's Heroes but I had a friend whose dad had fled Nazi Germany in the nick of time, and he loved it. Many of the shows actors were Jewish.
Schulz was just an ordinary German businessman drafted into the army. He disliked war, he hated the discipline, he liked a beer after work. He wanted the war to end so he could go back to his toy factory. I remember him telling IIRC General Burkhalter, "If you talk like that to me again, I won't let you have your job back after the war."