How to merge campaigns to theatres

in current campaings Most important thing is balancing technology so dividing by years will work i think
My suggestion :
Western front 1943- 45 : italy. France, low countries , west germany
Eastern front 1941- mid 43 : various battles from that timeline
Eastern front mid 43- 45 : same as the upper one
north africa 1942-43: same tech as tunisia but number of battles expanded (tobruk, el alamein e.g)
Balancing and authenticity system will be like this :
Lets say player choses to play with tiger ii vehicle in west front. Tiger ii used first in normandy so gamer will not be directed to monte cassino or sicily maps but can play in battle of rimni and Garfagnana and game should give that info to player. ( i know that some history nerds will say tiger ii never participated in those battles but according to dates’ they theoretically could.)
Custom matches can stay as custom. i really wanna see some japs and americans in same team fighting against russians and germans in winter uniforms at deserts lol
To decrease immense grinding’; players will have one team per timeline per faction. Opening same weapons for 77397th time for every single battle or have to grind soviets twice in lets say for moscow and rzhev for eg will be solved.
Possible pacific theatre : this will be a tricky one
We need 3 factions at least for the first half
1941- 43 :
British faction: burma’, singapore, hong kong
Us : solomons, papua , philipines
Japan : all fronts
With some additional aussie squads to us and indian squads to brits
44-45
Us vs japan in peleliu, philipines, iwo,okinawa, marshalls and gilberts(maybe) saipan guam etc
Vs japan

this would mean that if we get cold war, it will be impossible to reach it, because there will be so much grind, see in war thunder, you need to play a long long long long long time till you get your first jet, and even that sucks, so you need to grind until you get supersonic jet and even that one sucks, so you need to grind to the very end of the tech tree till you can play cold war