I personally think there should be equal tech for the same unit that gives different units in the same class.
Example infantry tech but each tech is different for each nations.
USSR would be conscripts.
Germany would be SS.
UK would be Homeland infantry.
France would be Resistance.
Italy would be Frogmen.
Japan would be “Koreans”
US would be Marines
ANZAC would be conscripts
China would be suicide bombers.
And then work around that. Or what you could do is set the tech upgrades to actual units each nation has that Axis and Allies don’t have set up. Like China being able to buy tanks as an example.