It’s interesting to speculate what would have happened if the Communists won in Germany.
That actually would have been Stalin’s nightmare, because ultimately the German Communists would try to seize control of the worldwide Communist movement from Moscow, and it could very well had still led to war between Germany and Russia.
Stalin discouraged any alliance between the Communists and various other Marxist parties (Social Democrats etc) in late 20's/early 30's Germany. This lead to infighting among the Marxist groups and their ultimate failure to coalesce into a stronger party.