hmmm, well Ive played those who tried to blob ppsh cons. Trust me, its nowhere near as difficult to fight as shrek blobs or rifle blobs. Which are really the only true blob threats. Maybe I shouldn't say gren vet is weak, its more like grens are the weakest of the mainline infantry in terms of durability. Idk its just whenever I play ostheer, it feels like the whole army is so fragile and collapses so easily with one good flank or light vehicle rush. Grens and pgrens aren't that good. Its all snipers, mgs and ostruppen. It feels like every time I try to use grenadiers vs americans or british that I'm just wasting my time and should just go build ostruppen, dont even think about pgrens other than for shrecks. So I think being able to buy g43 and lmg42 isn't that bad, I'd atleast want to test it out.
Cons don't have much firepower, but they are more easily kept alive and trade very efficiently and absorb well, when you get them to vet 3. Their purpose to rush into the weak spots on the front and throw molotovs and AT nades while tanks and support crews follow up. I'd prefer they not have that increased +9% received acc at vet 0 though.
For early game, I just think you have to follow up with a mg. if you have 2 grens, and 1 mg and they have 3 rifles, you can bait and suppress and follow up. they do not have FRP until T3 so that allows you to build defenses for their return.
I read the latest article about luvnest, the winner of the ESL I think.
http://www.companyofheroes.com/blog/2016/01/14/community-spotlight-luvnest
He states his favorite faction is OST because it's balanced and allows for more versatile strategies although it is more delicate to handle. So you are correct in feeling that way but I believe there are other viable counters since USF/OKW tend to be more limited to a particular style.