Increasing manpower requirements in regards to combat support units is a good idea, but I am afraid it will not do enough. Should players have to sink more manpower to staff hospitals, repair railroads, and man static AA? Absolutely. HOI4 does a poor job of showing the "rear" area units that were not captured by Hollywood and historical documentaries, which instead, spotlight and romanticize the frontline combat personnel. Maintenance units, field hospitals, signals, and logistical services should require more personnel than currently represented in the game. Again, however, I do not think this will be enough.
To seriously limit the size of militaries with historical constraints, HOI4 needs to overhaul its economy system and that is asking alot -perhaps even a recode of the Clausewitz engine. What made Hitler uncomfortable about deploying a massive 3 million man army in Operation Barbarossa was economics. He knew that Germany could only support such a massive military force temporarily, even though only a small portion of it was motorized. This was because every soldier drafted to the front, is one fewer, healthy working male to work in the factories, farms, and offices of Germany. HOI4 does not adequately penalize conscription. Every new division should decrease production by a little, but in HOI4, nothing happens to production unless you change conscription law. Fascists can make the citizenry, banks, universities, and corporations cough up all available capital to pay for the war effort, and make up the difference by leveraged borrowing that increased the money supply. Hyperinflation was avoided through draconian price control efforts. Therefore, paying for such a massive military was not that big of a problem for Axis and Comintern. However, resources were still a constraint. When the Reich raised new divisions, there were less workers in the mines, factories, and workshops that provided the raw materials and manufactured equipment needed for those divisions in the first place. This was not that big of a problem early in the war, because the Reich could conscript German workers to train as reservists, then send them back to their civilian jobs, then be mobilized for a short Blitzkrieg campaign, then return them back to work again. As a result, Germans were themselves building the weapons and ammunition that they would later use themselves. However, for Operation Barbarossa, Hitler needed the entirety of the manpower pool, including the already trained reservists, in the field - immediately and for more than just a month. Of 7 million men called up for service in the field, 3 million were earmarked for combat units in the Eastern Front. Hitler expected a short campaign and hoped to immediately downsize the Army to just one third of its initial strength, and send the soldiers back to the home front and start manufacturing the weapons for an air and sea war against what he saw as the bigger threats, the industrial civilizations of U.S, Britain, and her colonies. As a result, when victory did not arrive on the eastern front, this spelled disaster and panic in Hitler's inner circle. He now needed more men on the front to hold back the Soviets, but also more men in the factories to meet the massive ammunition and weapon procurement requirements of the Wehrmacht. Unfortunately, more for one would mean less for the other. The Nazi solution was extensive exploitation of slave labor, justified by their racial dogma. More and more of the Reich's armaments were being made by non-Germans, POWs, and workers abducted from occupied territories, working in harsh conditions to provide the material for the Germans being sent to fight. Some were paid and some were just slaves. The question is, does the community want the developers to model this? It seems it's already been abstracted somewhat through La Resistance's system of compliance and Occupation Laws, and there's already conscription penalties that modify factory output. My opinion is that this current system is inadequate, but a realistic system that matches the historical narrative described above may be hard to stomach. HOI4 players enjoy min-maxing production. Implementing these historical economic constraints would then require HOI4 players to min-max policies of mass-murder and slave-labor. We're potentially opening a can of worms here, and it's a touchy subject. One could argue that the devs should have no problem modeling this because we can look to Stellaris for examples of this brutality, but you have to consider that HOI4's theme is based on a world war where these events did happen in real life, and only 80 years ago . . . not some fantasy galaxy with aliens - but with real people. I'm not sure if this community is willing to go down this path.
Rearmament meant that German workers and families were rationing necessities and foregoing luxuries so that Germany industry could build bombs, bullets, artillery shells, and aircraft instead of consumer products. The lack of consumer goods, the undertaking of massive austerity, and the sacrificing of personal income to tax hikes to pay for the war, were all done willingly and enthusiastically (somewhat) because Hitler promised the German people an increase in the standard of living in the future (Lebensraum and Autarky by seizing resources in the East). This means that the civilian population can accept immense sacrifices and maintain stability only if they are convinced that the war will be short and temporary, and pay-off massively for their future generations. There should be stability penalties for offensive wars that generate too many dead or last too long, especially in proportion to the size of the military and the extent of conscription.
