None of the German tanks are accurate representations of German WWII types. They are all post war US variants. ie. M47 Patton Tanks. [Still a mistake, but an elaboration: This is a common problem in depicting German tanks: few, if any, survived the war. The few museum examples wouldn't be released for movie work, and certainly WHERE, some 20 years after the war, would one find a brigade's worth of running Tiger II tanks? Never mind that Kampgruppe Pieper, which Hessler's command is loosely based on, actually used Mark IV and Panther tanks. There was one King Tiger battalion, and it was in reserve well behind KG Peiper. The M47s versus the M24 Chafees (mistakenly called "Shermans" at times) is a fairly accurate comparison of the respective sizes, firepower, and other combat capabilities of the respective tanks. Some other movies, like "Kelly's Heroes", have their "Tigers" mocked-up with sheet metal, wire mesh, and sacking over a different type of tank (in that case, T-34/85s of the Yugoslav army are mocked up as Tiger Is, a fairly decent job).]
Robert Shaw's character is based on Kampfgruppe Jochim Peiper of 1st SS Leibstandart Adolph Hitler, Panzer Division. Peiper was a ruthless but extremely effective officer who had learnt his trade in death on the Russian front. Peiper survived the battle and the war and although he was initially sentenced to death for his part in the Malmedy massacre his sentence was commuted. He was killed in France in 1976 when his house was firebombed in a revenge attack.