I do not think the 1942 and 1943 Kharkov disasters were due to "junior officers" failings. Lack of willingness to risk Stalin's wrath by going to the defensive by commanders was important but mostly it was not detecting the significant German reserves building up on the flanks of the advance in time. I suspect the red army had a lot less communications equipment than the Germans so, even if the local commanders had been free to react they may have lacked the means to do so effectively. In 1944-45 two thing schanged usually the Germans lacked local reserves capable of major counterattacks and the introduction of "logistical stops" created a lot less opportunities for them. The 1944-45 red army didn't resort to the sort of "give all available fuel to a Kampfgruppe and try one more push" tactics that were so common in German late 1941 operations, and they had no need to take such risks that would play unto the German strengths (high quality low level leadership/initiative), while multiple attacks and reinforcing success played into the late war German weakness (brittleness of the "non elite" divisions), and so the steamroller brought them to Berlin. The red army nonetheless did conduct some spectacular long range operations to create the various historical "pockets" and in the final campaign against the Japanese. "Elastic defence" could be effective as it allowed limited in the initial shock better and put the mail line of resistance out of range of the massive Soviet artillery so partly negating it's effectiveness, but troops are at their most vulnerable when pulling back and ran the of the attacker generating sufficient "momentum" to shatter the defender is high.