An interesting historical tidbit...

"Blitzkrieg" is an invention of British propaganda - the Wehrmacht never used that term to describe their method of warfare. The Wehrmacht also never had any such a comprehensive and holistic methodology of combined-arms operations. There was one country, however, that did - the Soviet Union. Soviet military theorists spent the better part of the 30s coming up with some of the most forward thinking ways of actually waging modern warfare. It was called "Glubokaya Operatsiya - "Deep Operation." It certainly wasn't perfect or fool proof, but it was years ahead of anything being thought about in Britain, France, and even Germany. These ideas helped the Soviet army inflict the very first defeat on the Axis powers during WW2 - the battles around the Khalkhin Gol river in 1939, where the Soviet Union absolutely trashed the Japanese 6th Army.

By the time the Wehrmacht invaded the Soviet Union in 1941, it was all gone - destroyed by Stalin. One of the main architects of "Deep Operation," Mikhail Tukhachevsky, was dead - tortured and executed on Stalin's orders, along with God-knows how many of the Soviet military's brightest. Even Yakov Smushkevich, who commanded the Soviet air elements at Khalkhin Gol that was so critical to the Soviet victory and was known for his tireless efforts to improve the training of Soviet pilots, wasn't spared - tortured and executed.

It wasn't even limited to the military. Konstantin Chelpan, the lead engineer who designed the engine for the legendary T-34 tank, wasn't spared - tortured and executed.

It's not difficult to see why they got beaten so badly at the start of "Operation Barbarossa" - the Soviet Union had essentially been sabotaged by Stalin.