Just change def bonuses for OKW veterancy - problem solved. It's very hard to blob as Wehr or SU just because of their unit armor.
Wrong the problem is not "solved" you ignorant goon. OKW isn't the only faction that's abusing blobbing and it seems that only because it is a German faction that anyone gives complaints towards it any sort of credence. American riflemen are more than capable of blobbing regularly simply because they have extreme durability, accuracy, damage, and rate of fire compared to similar units.
Or Shocktroops their armor and smoke grenades make it near impossible to kill any significant amount of them before they can close in, wiping them is extremely difficult and if you can't do it, you'll eventually have blobs of 3+ Shocktroops wiping everything in their paths.
Conscripts, cheap upkeep despite same initial manpower cost as Grenadiers. Easy to upgrade with PPSh's and they are numerous, couple them with penals or just spam them alone and you'll provide more than a headache for the Axis factions.
If you want to actually solve the issue you need to put more emphasis on the suppression abilities of the machine gun, not just the German but also the Allied variants. While Wehrmacht will have options to counter maxim spam with doctrinal and non doctrinal abilities (Mortars and Mortar Smoke Barrages), OKW suffers heavily from it with no real smoke or incendiary abilities.
Americans basic line infantry which is also their best unit besides Paratroopers actually has an overabundance of smoke with smoke grenades (bad idea giving them that, should have given it to some other unit) making MG's practically useless as they are.