I'm specifically asking about this part:
Soviet commanders encountered the doctrinal German response to a mechanized advance; the leading German units gave ground quickly, luring the enemy tanks into a line of antitank guns that always followed immediately behind the spearhead.
In David Glantz's "When Titans Clashed" about the very first days of Barbarossa. I've also seen this response to British tank advances in North Africa. So, I'm wondering who wrote this, what made them consider this idea and why didn't others also come up with it prior to clashing with Panzer units.
You're asking two different questions here. The question of "Who wrote German tank doctrine", and "who developed the idea of the PakFront", or at least the anti-tank ambush.
The first one is easy. Under Von Seeckt, the German Army took a long hard look at what to be learned from the Great War, and they concluded that the correct answer was Bewegungskrieg, maneuver warfare. Then the question became how to incorporate the modern technologies, to include tanks, into this concept. Enter folks like Ritter von Eimannsberger or Ernst Volkheim who thrashed out arguments in the professional journals.
The doctrine itself was basically created under Oswald Lutz. Eimannsberger was retired by the time the Panzer Divisions were stood up, Volkheim had the benefit of experience at the joint German/Soviet tank school at Kazan in the late 20s/early 30s but was also not in a position to do much but advocate. Lutz was the man in charge of it all.
With respect to the anti-tank doctrine, I have a suspicion, but no evidence, that it was created ad-hoc. Certainly the idea of concentrated anti-tank firepower was considered in the 1930s and 1940 or so, as evidenced by German thinking on anti-tank vehicles, but such vehicles ended up not really being produced in mass numbers until the mid-war. If the AT guns couldn't go to the target, I guess someone figured the targets would have to be brought to the AT guns.