Why It's Bullshit:
Despite the copious stock footage of B-17 and B-29 bombers employed by the History Channel, World War II was still largely about horsepower. Literal horsepower.
And the Howitzer was powered by trained fire mice.
The Soviet Army had at least 3.5 million horses in service and deployed tens of thousands of mounted cavalrymen. They would have relied even more heavily on horse-drawn transport had the U.S. not played the role of shady wartime used car dealer. Now, you might expect as much from an army that famously didn't have enough guns for all its soldiers, but they weren't the only ones who relied heavily on horses.
The German "war machine" was actually less gears and sheet metal, more flesh and bone. When World War II began, horses outnumbered vehicles in the Wehrmacht by a good 3 to 1, and that figure only got worse as the war progressed and vehicles crapped out. When we think of the German army, we think of panzer and tiger tanks, but even the famous panzer armies had 15,000 more horses than motors. And here you thought those fancy jackboots were just for style.
Bundesarchiv, Bild 183-E10457 / CC-BY-SA
If there was such a thing as a "stately" blitzkrieg, you'd be looking at it.