While a nondoctrinal mg would help, I would rather see volksgrenadiers reworked. Make them cost 300 mp and more popcap, with better stock rifles (grenadier stats?). After 1 truck is built, they can upgrade to either 1 panzershreck and the ability to build sandbags, or 3 STGs and some kind of utility ability (smoke?).
This way, blobbing volks becomes less of an issue, due to their high cost. It will also lessen OKWs propensity to float.
In return, OKW finally gets a good scaling basic infantry force, which can be useful on the assault with STGs, or on the defensive with their rifles and sandbags. It will also make OKW feel more like the specialist army that it was originally, and make OKW more decision based as to where they want their munitions going, making them feel more 'starved'.
Thats just my view on the matter though.
I kinda disagree with this, Volks IMO are actually at a good place - they're good for holding the line/stalling/meaning that if a unit rushes up against volks, they lose models. I'm perfectly fine with this. (maybe their higher vet needs a bit of a buff so they are actually competitive AI at endgame, it doesn't have to be they are awesome at AI but enough to use them defensively against high vet Allies.
The problem with OKW atm is that the elite units (Fallschirmjagers and Obers) are severely underperforming - They just don't kill infantry fast enough for their MP cost and are really squishy.
Frankly, I'm perfectly fine with Volks being as weak as they are (except at higher vet) and I'm perfectly fine with OKW not having a non-doc suppresion platform other than Kubel, but make the elite infantry as strong as they should be.
That way, OKW will have a decent AI Infantry counter while not being too strong earlygame.