You are correct. They suffer against suppression platforms.
If Vickers were performing like an MG42, OKW would also have issue vs Vickers. 50cal comes too late, and USF doesn't really need force multipliers to win the AI fight.
Doesn't this imply that it is the Soviet maxim that might warrant a look at then?
What if maxims acted like vickers in terms of suppression? Vickers love to get kills, but they don't lock units into place like nobodies business.
Off the top of my head, I'd say key changes that would benefit OKW without breaking things further are:
Volks incendiary nades t0 side tech. 100m 10-20f. Allows quick response to garrisoning without having to invest all the way into the next tech.
T0 MG34, no truck needed.
ISG smoke barrage.
Reduction of medic and repair side tech costs by accommodating the costs into things like truck setup costs or forward retreat point upgrade. (Side tech of Flak gun to unlock panther seems quite feasible.)
The more extreme option is to move Obers to medic truck, give them a (double) panzerschreck upgrade. Reduce cost to 340-360. LMG34 becomes upgrade unlocked with flak truck. The lazyman's idea is to throw OKW a clone of Stormtroopers somewhere before the time Obers currently hit the field.
This idea frees up Sturmpios from having panzerschrecks and gives them the options for something like smoke grenades, which is entirely appropriate for the squad. And THAT could unlock when a truck sets up.