As I said in the beginning the real problems mainly starts with 2vs2 and get worse after that. As far as I know, OKW gets the mun from the caches that Ostheer mate builds... so there is no difference then. Just double shrek on five man squad in a pretty good doctrine.
I mainly play 2v2 and 3v3 as well and rarely encounter Schreck blob problems. This might be quite rank dependend (not that I was high rank though)
As I said, Panzerfüsiliere are a bit of a different thing. I don't think that they are misplaced though since both Axis factions pay a lot of opportunity costs. As USF/USK you can dump AT on your pioneer squads to make them more usable. Also their popcap is quite cheap and they are cheap to build which allows you to have two of them running around in the late game anyway since you need them for repairs which makes them not bleed as much. Pfussiliere and PGrens are both comparatively expensive and you cannot spam them without sacrificing infantry field presence. They are the mainline infantry and usually used to contest points against Allied infantry in the mid to late game. But using them with Schrecks takes away most of their AI capability. Pfussies scale badly without their G43s against infantry, while the combat power of PGrens gets literally halved. Getting bazooka/PIATs on the respective engineer unit however does not cost you much. Also both of them do not have snares.
So to sum it up: I agree that Axis get 'cheap' PSchrecks when just looking at the stats, but I think it is fair because of higher costs in the AI departement, population and having less flexibility. At least compared with bazookas. As I already said, PIATs could use a bit of a rework.