But Hitler already knew (or ought to have known - he was good at ignoring bad news) that there was no possibility of Japan attacking Russia. Japan had already clashed with Russia in 1938, and had fared very badly. One of the most influential but overlooked battles in history was Khalkin Gol, fought in August 1938 (before WW2 had officially started - go figure) in which the Russians routed the Japanese.
This battle is significant for three reasons. One, it made the reputation of Georgy Zhukov, who played such an important role later in the war: two, it demonstrated the effectiveness of the massed tank attack (it was the biggest such attack in history to that point); and three, it caused Japan to turn from a mainland Asia approach to a wider Pacific approach. In many ways, Khalkin Gol was the cause of Pearl Harbor.
As far as I know there was only one instance of either Japan or Germany assisting the other during WW2 - which came when a Japanese submarine sank a British merchant ship in the Mozambique channel, which ship was carrying supplies for the Eighth Army. As for your hypothesis: there are many things that Germany could have done differently that might have increased their chances against Russia. Possibly the most promising would have been to convince the Finns to advance beyond their 1939 border to complete the encirclement of Leningrad and to cut the rail links to Murmansk and western supplies.
But Russia was (and is) huge and rich in resources. Given that even had they wanted to, Japan could only have mounted a token attack from the east (because most of their resources were directed against China, not to mention their other Asian conquests) I can see no way of Russia not emerging victorious in the long term.
I cant really gove you an answer,but what I can give you is a way to a solution, that is you have to find the anglde that you relate to or peaks your interest. A good paper is one that people get drawn into because it reaches them ln some way.As for me WW11 to me, I think of the holocaust and the effect it had on the survivors, their families and those who stood by and did nothing until it was too late.