Simpkin's 'Deep Battle' was written with John Erickson's participation, and much of the material on which it was based was originally researched for Erickson's 'The Soviet High Command and the Road to Stalingrad' and/or for Simpkin's own 'Red Armour' and 'Race to the Swift'. Simpkin wrote before the Soviet Archives were opened, and used the periodical 'Voenno-istoricheskii Zhurnal'.
Simpkin and Erickson were important in the development of western understanding of maneuver warfare leading to Airland Battle Doctrine - see the sources quoted in
www.en.wikipedia.org/wiki/maneuver_warfare.
Simpkin's view was that "no reasonable person can question that Soviet writing on the operational art is streets ahead of anything produced by the Wehrmacht or in the post-war West".
The criteria for good performance of an air force in maneuver warfare is, IMHO, the speed and effectiveness of its response to the presence of enemy anti-tank weapons and machine guns. This was first defined in 1918 by the British. It requires real time action that is dependent on direct communication between CAS and ground troops, and it is best provided when the CAS is under command of ground troops.
The RAF's 2TAF in WW2 was deficient both in speed and effectiveness, and was never under command of ground troops. My specific interest is to find a comparison with that provided by the VVS which was, of course, an army airforce.
Tukhachevskii himself stated "the paradox between centralised direction and low-level freedom of action".
Tony