Memes

Defeating the Nazis was a pretty big deal, especially considering the Red Army was responsible for 4/5ths of total Nazi deaths.

Quoting and re-emphasizing myself, here. Stalin absolutely played a major role in how the Red Army was organized and how millitary strategy unfolded. It was of course the Red Army that did the fighting, but they could not have defeated the Nazis without officers, generals, and of course the politburo (Stalin included) all playing their parts at different levels.

Just as a footsoldier has a great grasp of their immediate surroundings but a poor understanding of the battlefield, and the battlefield commander a great underatanding of the battlefield but a poor understanding of the immediate surroundings of the footsoldiers as well as the entire front, the general also plays their role at a further level of abstraction, as did the politburo. Stalin absolutely played a part in the defeat of the Nazis, moreso than Churchill or FDR, as an example, as the Red Army was far more directly responsible (and the US in particular cloaked how much trade they were doing with the Nazis even during WWII for private profits).