This film has about as much relationship to the actual history of the Battle of Stalingrad as the "Sound of Music" has to the real von Trapp family. About the only accurate portrayal is that yes, there really was a Vasilii Zaitsev who really was one of the hero snipers of Stalingrad.
Of all the errors the one I find most egregious is the complete omission of one of the true heroes of Stalingrad: Vasilii Ivanovich Chuikov, the general who took command of Stalingrad in Sept 1942. The man who declared "We will hold the city or die here; there is no land beyond the Volga!" Gen. Chuikov, whose tactics and use of "storm groups" and snipers held the desperately beleaguered city through not only house to house battles but floor to floor in the same building. To omit Chuikov from a film on Stalingrad is like omitting Patton from a film on the Allied advance across France.
This is not simply Hollywood license; this is a distortion of history. It speaks to the contempt that the film's producers hold for the American viewing public that they had to use Khruschev because his name might be recognized rather than present historical fact.