Here are some problems that Enlisted’s progression system has:
1.Same weapons have to be unlocked again and again
2.We have to unlock a bunch of things we are not interested in before getting what we really want to use.
3.We are forced to play certain squads to upgrade certain weapons(especially rifles)
Here is the summary of what I am about to suggest:
-Faction techtree, weapons/vehicles/equipment are categorized into branches
-Can use exp earned from one campaign to unlock equipment from other campaign.
-‘Baseline equipment’ in every campaign
Each faction has their own techtree. Each techtree has several branches depending on country and weapon type(rifle, assault, mg, AT weapons, mortar, flamethrower, tank, fighter, attacker, mine, grenade, bag). Weapon upgrades, a part of squad upgrades, are moved to the tech tree.
Every weapon can be used in specified campaigns(for historical accuracy). In the current system, the sum of exp from squads(total exp) goes to the campaign levels. And the exp earned by a squad(squad exp) is used for the squad upgrades.
In the new system, the total exp is used to unlock weapons in the tech tree. So, the exp from Moscow squads can be used to unlock Berlin equipment. Theoretically, a player can play only one campaign as allies and unlock all allied equipment. However, there is a system to encourage playing different campaigns. When using exp from one campaign to unlock equipment from that campaign, a 50% discount is applied. Let’s suppose 40000 exp is needed to unlock Grb-39, an AT weapon used in Moscow, Stalingrad, and Tunisia. In order to unlock this weapon, only 20000 Moscow/Stalingrad/Tunisia exp is required. A combination of different exp is possible as well(10000 Moscow exp + 20000 Berlin exp = 40000).
After reading this, one can say: there is a problem when a new player wants to play late-war campaigns, such as Berlin. Most of Berlin equipment are far from the start of the tech tree, so a new player have to spend a lot of time to unlock weapons. To resolve this issue, baseline equipment, one from each equipment type, are provided. These weapons/vehicles can be unlocked even though previous equipment is not researched. For example, baseline equipment of Berlin Axis would be Kar98k Kriegsmodell(rifle), mp3008(assault, next weapon would be mp40), mg34, Pz.4 J, etc. The baseline equipment that a 0 hour player receives at the start are rifle(bolt action), smg, tank, attacker, and fighter. Baseline equipment can be unlocked without researching previous equipment, but it has a disadvantage. Before preliminary research is done, further research can’t be done.
Let’s suppose the axis mg line is in the following order.

Mg34 is baseline equipment for the Berlin axis(highlighted in yellow). A new player starting in Berlin can unlock the mg34 and research its upgrades without researching previous weapons, but mg42 can be researched only after 1)mg13 and zb26 or 2)Breda mod.30 and zb26 are unlocked. Unlocking all three weapons is unnecessary.
Extra suggestion: How about the soldier class unlock and upgrades?
I suggest that the soldier class unlocks to be rearranged, so that players can unlock whatever class they want first. Riflemen, engineer, and assault classes will be unlocked for beginners. Soldier class upgrades remain in the squad upgrades, just like the current system. How about getting the ‘II’ and ‘III’ classes? I think a player must play with the ‘I’ squads thoroughly before getting the ‘II’ squads. So I suggest that ‘II’ class unlock to be possible after all ‘I’ class upgrades are complete. Squad exp is used to upgrade squads and total exp is used to unlock new soldier classes. When a new soldier class is unlocked, a new squad is given. For example, when a player unlocks all upgrades in assaulter I squad with squad exp, the player can unlock the assaulter II class with total exp. Once the research is complete, the assault II squad is given.
Reminder:
total exp: sum of exp from squads
squad exp: exp earned by a squad
Thanks for reading this suggestion post. Please ask if you have any questions related to the suggestion.
it’s just my opinion.