The Soviets did have a nightmare stopping the Germans. It took two years to do it. Be more specific.
This right here needs some serious support. Given not only the advantage in material production and men, but also the massive improvement in troop cohesion, and the chain of commands ability to carry out orders, the situation was not the same as it was in 1941, and the Germans had no hopes of regaining the strategic initiative following Kursk, regardless of Hitlers orders.
That bolded part is straight up wrong. The majority of the German army were committed to the Eastern Front. Read some serious history books before coming up with garbage like that.
Mark Solonin's The Cask and the Hoops offers excellent analysis of the subject in question, in regards to Soviet defeats of the early war in particular. Chapters from his book are available free, online with authors permission here:
Mark Solonin. Historian's personal webpage.June 22 (The Cask and the Hoops)
The important thing to consider is that the key factors behind the inability of the RKKA to fight even a defensive battle, despite advantages in men and especially equipment, the factors responsible for German success, was not the prowess of German generals, or even the professionalism of German soldiers (which Soviet authors like to talk about, and which is really code word for something else). The defeat of the RKKA was the result of the complete lack of desire to fight, and complete inability as well as lack of desire, of the officer corps to lead the troops in combat. The vast majority of the RKKA casualties from the early war surrendered without firing a shot, and the vast majority of armored vehicles, tanks, artillery pieces, were abandoned without a fight.
This is what changed by 1943, and this is what is responsible for the defeat of the German Army following Stalingrad, and later Kursk.