The Russian Army was never that great. Even in World War II, they went on a rampage, but they weren’t efficient at all. The war value of a Russia soldier was far lower than, say German soldiers. (By effectiveness)
The Soviet Union is estimated to have suffered the highest number of WWII casualties. As many as 27 million Soviets lost their lives, with as many as 11.4 million military deaths joined by up to 10 million civilian deaths due to military activity and an additional 8 million to 9 million deaths due to famine and disease. Those totals do not include the more than 14 million Soviet soldiers who were wounded during the war.
Among the Soviet Union's 15 republics, Russia withstood the highest number of casualties, with 6,750,000 military deaths and 7,200,000 civilian deaths. Ukraine tallied the second-highest casualties, with 1,650,000 military deaths and 5,200,000 civilian deaths.
In comparison the US and UK lost about 400,000 each and that includes loses in the far east (Japan).
The eastern front was brutal. And the Russians will never forget it.