You often mention the coefficient Man2gun, but it does not take into account the very essence of army mechanization - tanks! It turns out that if a player creates tank divisions to the detriment of infantry, then Man2gun falls - not logical.
The difficulty is that from the number of tanks of the USSR it is necessary to subtract the "tanks" completely obsolete and, in fact, tanks that are not. Of the 21k at the beginning of the war, only a little more than 1k were new. For example, if you recount your formula in this order, then the Germans = 116.2, the USSR = 88.5 (assuming that 80% of the tanks for the 37th turn are modern).
Obviously, the Man2Gun index is not an extact value specifying how the game is going, but I still think it holds some value.
By comparing the number of guns to the number of men in the Wehrmacht and the Red Army, you get a figure telling if the respective production systems are able to keep replacing lost guns in the fighting units. If this number rises, the production system is trailing behind and, over time, you will have a problem.
By wathcing detailed attack reports, I have come to the conclusion that it is in fact the guns that are responsible for causing most of the casualties suffered in ground combat. Especially when taking into account that there are generally fewer men operating a gun than are in a squad. You get more "punch" pr soldier in a gun unit than you do for the same soldier in an infantry squad.
In theory, you are right that the number of tanks will have an adverse effect on the man2gun index, but I do not think this is terribly important. Of more impact is the nature of the guns used. The Man2Gun index treats both an Anti Tank Rifle and a 155mm howitzer as one gun, while they are obviously of different value to the combat unit they are assigned to.
To sum up, I simply use the Man2Gun index as a simple way of tracking the development in quality of the various infantry forces that makes up the majority of the fighting forces on both sides. The system is far from perfect, but I think it adds some value for the effort I put into tracking it (I automated the tracking, so I get it for free).
On a different note, I guess I will have to look for another brilliant Stalin quote.
We need only to kick in the door, and the whole rotten structure will come crashing down.
Adolf Hitler, on the eve of Barbarossa.