It’s not that the “level of efficiency is effectively rather low” it’s “every time you try to take this Bofors out it’s going to cost me drastically more resources than the cost of the Bofors.” Hell, most of the time walking into the Bofors sight for the first time will cost a Grenadier, Volks, or scout car. There is really no reason not to choose the Bofors, comparatively the AEC is nowhere near the power level and a teller with kill a full health unit most of the time.
Alright. I am just going to step in here and say that this is absolutely false.
Meanwhile the OKW Luftwaffe Flak gets decrewed by a single grenade. If static weapons are meant to take a hit, why are Brits the special snowflake that can brace? I would very much welcome a significant price increase to the Luftwaffe flak for the ability to stand nades and brace.
The 2cm flak can under no circumstances ever be as potent as the bofors. This is simply due to faction design. To get a bofors, one must sacrifice the AEC, and with it, the only aggressive AT tool that they have up until medium tanks. You can outmaneuver and cap around Bofors. Against a very aggressive emplacement user that has placed the emplacement far forward. You can even baserush the enemy and kill him with an all-in type strategy since it only has machine guns to defend; though this latter strategy is only really available for OKW.
The OKW flak 2cm has none of the weaknesses associated with the Bofors. OKW has shrecks(soon also snares), the puma and the Luchs. Their base is also defended by 2cm flak guns that defend well against light vehicles. If the 2cm flak would be like the bofors, you could just plop one down on one side of the map and focus all your attention elsewhere with no fear of enemy light vehicles pushing off the map and killing you.