When looking at history that way, you fail to consider that events do not happen in isolation. so when you consider a single "what if?", you have to consider a countless number of other ones. You cannot impose a limited set of conditions or possible outcomes at your whim.
But lets play your little game anyway. First of all, Germany would not have had that many extra aircraft and crews at their disposal in Russia, so it is debatable whether it would have made a big difference. The Germans certainly weren't going to leave their conquest of western Europe without significant air strength and they were certainly not going to reduce it to less than parity with England, which was not a weakling by any means.
Second, while Germany might have attacked Russia a bit sooner, they couldn't have done it in 1940. As it was, the plan was for May 1941, but it got delayed 5 weeks, in part due to the weather. They couldn't have gone earlier than May due to the spring mud season, and then there was the required time to move forces from the western to the eastern front, so would 5 weeks have really made that much difference? Probably not.
You also cannot ignore probable extra assistance given to Russia by England and the USA, nor can you ignore the probability that British forces in the Mediterranean would have been bolstered, putting more pressure on Germany in that theater, especially in Greece and North Africa. More American and British resources would have probably been sent to the Orient, changing the dynamic and course of events there. Events that could not have favored Germany.
Even if Moscow, or Leningrad, or Stalingrad had fallen, the Russian military and people would simply have fought on. Most of Russian production had already been moved so far east that it was essentially out of reach to Germany. The RAF wouldn't have done nothing, and in fact an aggressive bombing campaign of Germany would most likely have begun sooner. A British expedition to the continent, even possibly through Murmansk would have complicated things greatly for Germany, resource-wise. They could not escape a 2-front war.
Could Germany have done better in Russia? Probably. Could it have changed the outcome of the war? No. Final conclusion to your question? Checkmate!