I think the point is that the IJA could not have made a scratch against the Soviet war machine. The Japanese did not have the reaction time or the conceptual understanding for waging a continental war against the Russian Army, to say nothing of their hardware. This means the Soviets defeat IJA with their far eastern forces while the western military districts remained to engage Hitler's invasion.
Mein Kampf is pretty damn clear on the basic principals of the Nazi program if a bit vague on the details. That is probably because Hitler hadn't decided on the implementation at the time of writing. Racial purity, imperialist conquest, maximum exploitation of conquered territories by linking them to the heartland and eliminating any non-German who is not useful is all in there.
G. Megaree's War of Annihilation also illuminates Nazi intentions through an examination of actual economic war planning in 1941. To put it simply, the Nazi strategy seemed sum up as 1. go east, 2. kill anyone not useful as part of a slave labor workforce, and 3. hog all the agricultural and mineral resources.
You might also look into the Mitteleuropa Plan conceived during the first weeks of the First World War in which control of Central Europe (Ukraine & Belorus included as per Brest-Litvosk Treaty) and its resources was deemed a long term strategic goal.