Synchronising in with the World War Two channel as they go over the German invasion of Poland, a discussion of how the Germans went from "Bad Germans, no tanks!" to "What hit us?" in the period between 1918 and 1939.
The written article on Panzerjager referenced: https://worldoftanks.com/en/news/history/The_Chieftains_Hatch_Parallel_Evolution/
To be clear, Wargaming/WoT is not involved in this video, I just mention them for background.
Selected sources:
The Challenge of Change: Winton & Mets (Chapter by Corum)
Storm of Steel: Habeck
Frieser: The Blitzkrieg Legend
Panzer Tracts: Jentz & Doyle
Interview with Panzermuseum Director Raths. (Upcoming video)