Yes the premise of an Army Air Corps Colonel who assembles a team of sabotage operatives inside a Prisoner of War camp in the heart of Germany is a little far-fetched. And the part that the producers played with the Gestapo and the Luftwaffe were stretches at best. The fact is that facts play a very small role in the whole of the program. Many times continuity is not what it should be and people change names and jobs from week to week.
All of those things aside you will find this a hilorious show. Bob Crane was a funny guy and casting him in the part of Hogan gave it a much more natural feel. Werner Klemperer and John Banner did incredible jobs as the bumbling stalag Kommandant and the hapless sergeant of the guard respectively. The other bit actors who rounded out the cast did an incredible job of solidifying the thin beleivablility of the show. Some of my favorite episodes from season one were:Anchors Aweigh, Men of Stalag 13 ,The Gold Rush ,The Prince from the Phone Company, The Safecracker Suite. I loved the chemistry that they developed in their six seasons and I was sorry to see Ivan Dixon leave the show in the last season.