There's an argument to be made that Stalin was building toward a 1942 invasion of Germany and had plenty of tanks and planes, just more oriented toward offense than defense.
Stalin had 6000 tanks running on rubber tires with amphibious capability. Useless on the fields of Russia as few paved roads, but great for the German autobahn and an advance into France. They had to be abandoned when Germany attacked.
I don’t think Stalin was planning an invasion of Germany in 1942. He knew he was not ready for war in 1941, and the Non-Aggression Pact was his way of buying time to get ready. By 1942, many of the deficiencies I previously noted in the Red Army would have been rectified or well on their way to it.
Instead of fighting Germany, I believe Stalin would have resorted to economic blackmail. So long as the British blockade was in effect, the Germans relied upon the USSR for much of their economic materiel. Stalin would have choked it off, and demanded concession after concession. Eventually, Germany would have been reduced to economic vassalage. Of course, that was never going to happen while Hitler was in power. He’d rather fight than allow that.
Hitler either knew or strongly suspected this, and that’s why he “hit back first” in 1941. My opinion: Hitler had to attack the USSR, and he had to do it in 1941. There was not enough time after the Fall of France to do it in 1940. By 1942, it would have been too late, the Soviets would have grown comparatively stronger while the Germans would not. Do I think Germans had a chance of winning? No, not really. There are very few scenarios that don’t flagrantly violate “henkster’s law” that have the Germans beating the USSR.
But for Hitler to not try would also have been a flagrant violation of “henkster’s law.”
Soviet medium tanks ran on rubber tired wheels. That was a feature of the Christie suspension design which the soviets adopted for use in their medium tanks, like the T-34. The T-37, T-38 and T-40 amphibious tanks would have been of very marginal utility in any invasion. While the could cross a river without a bridge, they were armed with a single 50 cal. machine gun and only carried a 2 man crew. Hardly a weapon to plan an invasion around.