stalin was important but he is split with trosky, lenin, marx and a few others, hitler was on his own trip.
They're important in many different ways, but Stalin was and continues to be a very important and terrifying figure in a large part of Europe. Hitler's influence ended in the bunker he shot himself in. In the bigger picture, the Nazi's played a smaller role compared to what the Soviet Union/Stalin did.
Still to this day if you want to understand Russia and eastern europe in general, you need to understand Stalinism and how it affected everyone involved.
