I completely disagree here. Not being able to churn out 20 carriers at once by introducing appropriate dock facilities is hardly changing the game into a 'rigid system.' And even if it was, it is an emminently sensible suggestion that would prevent frankly ludicrous scenarios.
My example is only one of many limitations nations had placed on them by their their politics, economy and society in general that you don't have in the Hearts of Iron franchise. A more broad based one is the absurd idea that changing a minister can magically increase your manpower growth overnight, along with the idea that you can increase your proportion of national IC to consumer goods to reduce dissent at a steady, predictable rate. Removing these impediments, and allowing you to for example build massed carriers, or create an infrastructure 100 road across the Sahara if you wanted, without requiring the other huge, important logistic needs for such enterprises strikes a balance that is not perfect, I agree, but a balance nonetheless.
1936-48 is plenty of time to go a-historical if you want to.
In HOI2 that is all of 13 slider changes, and the scripted events and systematics get in the way of going ahistorical (officer purges in USSR, 2-2-6 incident in Japan to name two). There's not enough wiggle room to do truly interesting things in that context. If all you want to do is something like focus on controlling North Africa instead of attacking the USSR as Germany, that is much easier to accomodate, and can be done in scope of shipyards and such. But that is also severely limiting to the game's replayability.
It sounds like you basically want to be able to do very a-historical if not downright unrealistic things with HOI3...which is hardly the simulation of WW2 that you claim the game is and should be.
Yes, I would like to see how WWII would have turned out differently is Hitler had not been an irrational fool and instead focused on defeating the Allies before tackling the USSR. That 'what if?' desire requires a different set of circumstances and priorities for Germany that would have needed to have been started way before 1936 to come to fruition; the Kreigsmarine would have needed to be trained in a fundamentally different way from long before the 1936 time start. So, I require the game to be able to accommodate that, and it does so by not requiring shipbuilding facilities, for example.
The system accommodates, as best it can (at least in HOI so far, for HOI3 it's hard to say, obviously) player desires to see things through differently that require a degree of abstraction and gameyness. That's okay with me.