I didn`t buy the game yet, but reading those last observations I couldn`t avoid to associate it to a problem I see in any game simulating production. The fact is that players not only have better knowledge of equipment capacities than commanders of the time, being able to playtest them at will, but also some production variables are never simulated. Production wasn`t only a question of choosing the best weapon available and manufactoring it. Apart from the limitations of resorces, one had to deal with economical interests, conflicting points of view and necessities of high command, political pressures, already installed capacities and at least one point that could be simulated easily and which could compensate for all others, perhaps: opportunity costs. If one produces to many infantry and no tanks, that means that all production resources are pointed towards infantry production. Each extra infantry unit produced should become more expensive due to things like lack of resources, training costs (since most especialized resources were already used, like trained reserves, officials, etc), etc, which means that the marginal costs should be greater. People are being taken from one niche of production (were they do better) to another. On the other hand, tanks should become less expensive, since one has idle production capacity and spared resources. This would work also for different kind of tanks, since if you stop producing one kind of tank, you'll have idle capacity for the parts which are specific for this kind of tank. So, beginning to produce it again, should bear lower costs. I'm ignoring some points, like fixed costs, but for a game, a simplified model should work well, compensating even the other variables I quoted above. It's simple: just make things that are intensively produced in a short period of time more expensive for each produced unit and things that weren't produced, less expensive. So, players would have to balance production or pay the greater costs if worth it according to his strategy.
As I said, I don't know the game yet and it's editor, but that is a common problem with all games I know which simulate production. At the end, people tend to 'overproduct' one or two kind of units and game becommes dull and unrealistic.
Just my 2 cents.