I see that 2 see it differnent. That People haven´t an clue to bring in important Features and help with them to solve the Problem with the Lag later on.
With the real Numbers Economy, which working perfect, the later Lag-Problem of the Game get solved and it´s running smoother later on. That means the Buildup from Tanks for every Country, the correct Army-Config incl. Maximum Devisions and so on.
What the Economy belongs, in our real World you don´t have Iron, Aluminium, Fuel and similar from directly on. You have to make it from raw Materials. And the most Players wanna have an correct but easy to handle Economy System. And the Ultra - Historical shows how easy that is to make only for the Mining the Raw Materials, Refining Raw Materials and use the Endproduct for buildup what you want.
The only thing is that you need (and I have seen that in other very good Mods too with advanced Tech-Tree) other Factorys to convert the Raw Materials into useable Products. And that the existing Materials on the World Map get changed into the Raw Materials, that´s all.
So you get an correct Industry and Economic System with the existing things (Standard-Factorys, War-Factorys, Synth. Raffs [and with the Economyc Change the Synth. Raffs are much more important]) with the new Convert Industrys [Heavy Industry, Aluminum Mill or what they get called].
If then the Refit from Industry- / Economy R & D-Part come too, then the Economy Mix get perfect. The Groundwork is there the Devs have only to communicate with the Modders like the Modders do with the Devs.
The other Point for an Refit from the Economy, which have begunn with the Barbarossa-Patch [Supply / Streets / Railroad / Depots] is that if the R & D-Part get done correctly there you could not only reduce the Lagging later on on the World Map. You can get an better individual Industry-Management for the Countrys, you can play [Poland, Germany, USA, Canada, UK, Russia or whatever of the cool playable ones and the playable ones which come later on]. The Modders from Ultra have begunn work on to Refit the on that R & D-Tree in that Part.