This is a weird show. The premise is somber and horrible. Its a WW2 show about Allied soldiers in a German POW camp. Really nothing funny about the premise.
Yet it only works because Klink (commandant) and Schultz (head guard) are either really idiots or really working deep undercover for the allies. Actually the actor who played Klink, Werner Klemperer, would only play the role if Hogan came out on top each episode. Both actors were Jewish actors who fled Germany. wikipedia has a good background on this show.
I don't think it would have worked as a comedy if Klink or Schultz presented a real danger to the POWs. I always found it interesting that the show has been in syndication so long. Right now its on MeTV