You are indeed proving to me that changing any rule set is complex indeed and requires very thoughtful analysis.
Yes, that’s quite correct. An important point to remember is that a complex game such as Global 1940 is similar to other complex devices (such as automotive vehicles): they are systems consisting of multiple interrelated parts which are designed to work together in a particular way and which reflect many design choices and compromises. Sometimes it’s possible to make minor or even major alterations to some of those components without affecting significantly the performance the overall system, but sometimes even a minor adjustment to a single critical component can wreck the whole thing. (Take as an example the recent Galaxy Note 7 debacle. There’s been speculation that Samsung may have changed the electrolyte in the lithium-ion batteries to something less stable, or that it may have gone too far in thinning the separator which keeps the positive and negative sides apart so that the battery doesn’t short-circuit and overheat.) And design considerations have to take into account the fundamental question of what purpose the system is supposed to serve. A luxury limousine, a Formula One race-car and a semi-trailer truck are all automotive vehicles, but they’re all optimized to do specific jobs and they all place different leves of emphasis on different capabilities such as passenger comfort, baggage / cargo-holding capacity, speed, fuel consumption efficiency and so forth.