Historically accurate, well thought, good post.
As for models, I have more:
Have fun reading.
More modeling to do:
Bipods and tripods
Stationary and portable MG42 could have a difference in look. The “light” bipod MG42 is portable, while there could be a new “heavy” tripod look to replace the ones built by engineers. (The past-tense verb ‘assembled’ should be more precise here than ‘built’.) A tripod would bring more stability to the gun, and increase its accuracy. Well, due to game balance reasons these benefits could arrive later, but please do correct the workhorse of the Wehrmacht.
Give Bren a tripod!
According to WW2 official British TOE (Table of equipment and organization), each British infantry company has 5 tripods to mount Bren LMGs. A tripod made a Bren more suitable for defense, as it increased its effective range. It could also provide fire support for friendly units in an attack, for example by suppressing the enemy, keeping their heads down and away from windows. The tripod could be reconfigured to an AA mount. A 100 round pan mag could be used for this purpose. These tripod mounted Brens should be assembled by the engineer I, replacing the M1919 Browning, (If not then by a future HMG squad, which needs one soldier to carry the tripod and one for the Bren. Gunner could not shoot on the move.), and they should have the flexibility to change configuration to attack either infantry or aircraft.
Press to look at picture: Bren with tripod in use
M1919 Browning should get a tripod.
The M1919 Browning is the standard US infantry company support MG, each company has 2 of them. They also came with tripods and their realistic shot dispersion is way lower than the current state in game. This should be the Engineer II’s MG build but I wouldn’t mind if the British (Engineer I) received them via lend lease. The big thing is the gun’s accuracy. Currently 4 out of 5 rounds it fires at 150 meters/yards/arshini range misses the target.
M1919 Browning with tripod
Add new light AA guns:
Add a single barreled Flak38 AA mount to replace the AA assembled by German Engineer I in Moscow and Berlin. This would reduce the firepower of Engineer I’s AA, but would increase the Allies’ infantry and aircraft’s much needed chances of survival when they encounter this type of weapon. This matches historical reality, as the single barrel Flak38 was what the Germans most often had. The single-barrel configuration is 34 times more common than the Flakvierling. This would encourage the player to shoot more accurately with the weapon. In the Tunisian campaign, add the Italian 20mm/L65 Breda Mod.35 instead. As a dual-purpose gun, the Italian weapon was used extensively by the Italian Army against both aircraft and infantry. It is also capable of defeating the armor of light tanks: its AP shells could penetrate 30mm of armor at 500m range. The AB41 in game already uses the same gun. The developers could replicate the historical field mount for it.
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Against ground targets the gun fired armour-piercing rounds, while aircraft targets were engaged with a high explosive projectile that incorporated a very sensitive percussion fuse to operate against light aircraft structures. The latter projectile also had a self-destruct feature if it did not hit a target. The tripod platform of the gun provided a steady base for firing and against aircraft the gun proved very successful. Against tanks it was less effective, but any weapons captured by the Allies during the North African campaigns were usually mounted on the light armoured cars to provide them with more offensive capability than a machine gun provided and Portee to provide mobile air defence for armoured columns.
Yes, the British in Tunisia used captured Breda 20mms against the Axis.
The German Engineer II in Stalingrad and Normandy should have access to 37mm Flak37. The reason for this is the Flakvierling’s lack of punch against large aircraft in these campaigns, notably Stalingrad’s bombers. This gun would give ground troops the ability to drop bombers from the sky. It has a rate of fire of 160 rounds per minute, and is commonly used against ground targets, alike the 88mm flak and Flakvierling,
Flak37
The Western Allies should use the 20mm Oerlikon Mark II autocannon. It could be fed by either a 60-round drum or a 20-round box. It should be on the field mount used by both Oerlikon and Polsten guns. Engineer I could build the single barrel mount, while Engineer II- triple barrel mount.
Oerlikon



Effective range: 1,000 yards (914m) against aircraft with HE-I Mark 3 shell, USN Oerlikon gunners typically opened fire at 1,200-1,300 yards (1,097-1,189m) for aiming correction (absolute maximum range 4,800 yards (4,389m) elevated at 45 degrees: AA ceiling 10,000 feet (3,048m))
It took me a long time to find photos of single Oerlikons mounted on the ground, the web was filled with damn late-war Polstens or navy Oerlikons. I couldn’t find photos of multi-barrel land mounts except this one with three barrels.
In 1943 the Allies realized that 20mm mounts with multiple guns were just a waste of ammo and equipment, so they replaced the few with single barreled Bofors. The most common AA gun for the Western Allies is actually the 40mm Bofors. The US version of it is designated 40-mm Automatic Gun M1. Its effective range is about 4km, and I guess it could OSK (one shot kill) most Axis aircraft, so it better only be in Normandy with Engineer II.
Bofors
In the Red Army, there are three alternatives for light AA: 12.7mm DShK HMG, 25mm 72-K autocannon, and 37mm 61-K autocannon. The first two are a bit problematic during the Battle of Moscow and Stalingrad. The DShK lacks firepower against aircraft, even if it could obliterate light panzers using AP. Most of the them were mounted on vehicles. AA units equipped with infantry tripod mounts were busy protecting HQs and artillery, thus there weren’t much of them left to support line-infantry. The situation is similar for the 72-K: It wasn’t mass-produced until 1943. Most of the early versions were mounted on trucks or installed in fixed positions because of their original mount’s deficiencies. These issues made it a rare weapon for Moscow and Stalingrad. A heavier gun- the 37mm 61-K autocannon, was way more common. Its performance was similar to the Bofors, making it an ideal weapon to deal with bombers. I suggest they be added in Stalingrad for Engineer II to build. Because they are fighting very close to the frontline in Enlisted, they should get a gun shield. All of these AA guns are dual purpose, which means they could also be used against ground targets. Their AT capabilities are all considerable: The DShK can penetrate 15mm armor at 500m range; the 72-K could pen 40mm armor at 100m range with its AP round in theory; the AP shells of the 61-K reportedly can defeat 37mm of RHA at 60° at 500 meters range.
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37mm:

By the way, maybe allow the famous 88mm flak to shoot planes and lower their guns to hit land targets. It has the limitations of a long load time with insufficient crew. The ammo is heavy and it should be stored in ammo crates nearby. The amount of 88flak in maps should be reduced due to the OP nature of these guns.
88mm Flak18/37