I agree the real duel was nothing like seen in the movie. In Vassilis original full length memoirs “For us there is no land beyond the Volga” he claims a German prisoner told Chuikov that a Major Koning has been flown in to take out Zaitsev.
This so called Koning killed sniper Gryazev and shattered the scope of sniper Morozovs rifle. Vassili and his team went tracking Koning down when eventually Zaitsev and Kulikov found “Konings” area of operation-they searched for him over a weeks time and eventually Zaitsev killed this German sniper supposibly “Koning” Vassili and Kulikov went over to his body took his documents which read the name Koning on them. Vassili gave the rifle to Captain Batyuk and kept the scope as a trophy. More can be heard on the documentary-Russias War Series where Zaitsev tells about his experiances and the duel on it.
But again there is no proof of this German sniper being a Major or head of the sniper school in Berlin… as flamethrowerguy said the top 3 German snipers didnt have a rank higher than sergeant.
Regards