I did this as a comment on a separate post and it’s partly derived from other comments - but I thought I’d create a new topic for visibility.
I think having multiple squad pre-sets could be the the best answer to keeping inappropriate equipment out of certain maps.
Matchmaking would be carried out on skill, a map is selected and then you have to select from your own custom preset squads that are eligible for that map.
So you’d still have multiple squad sets for each faction, but the player base is no longer split and the tech tree still fits for unlocks across the whole faction. You just wouldn’t be able to equip late war equipment to your early war squads.
You could still queue as Germany axis for example - but you’d have an early, mid and late war set of squads - equipped to your liking - to choose from depending on the map/era. Not all factions would need 3 sets of course.
Sounds like a lot of squads to equip/manage, but it is what we already do now if you play multiple campaigns. Seems to me like the best balance between old and new and would prevent historical inaccuracy or imbalances in equipment as it would basically be the balance and accuracy we have now - just merged into one matchmaking queue.