That is not completely true. OKW has options to help out volks like PF, JLI, Falls and machine gun to slow down enemy blobs until Obers show up.
The second statement is even stranger since every other army would be purchasing their respective elites after having a standing army. Assault grens can be built without T1 so that is savings that can be used towards making PG while osttruppen are dirt cheap so aside from micro nothing is stopping the player from making at least 1 PG. Also since PG can come without T2 they can hit the field around 4 mins which leaves them as a massive power spike.
I was talking nondoc as Esxile talked about superior stock elite infantry. If you add doc in, then PF blob shows up by midgame and they don't even need Obers. Hell they can just meme with Falls or in the case of UKF (ab)use JLI until the UKF player RQs. MG34 is not a real issue imho considering the plethora of USF smoke abilities.
Realistically you won't get PGs that quickly, unless your opponent is being strangely lax (1v1) or it's teamgames (which is another matter entirely). Having such a weak force out there is asking to get shot to pieces by allied mainlines outnumbering you, esp Rifles. To that end OST extremely often get a Sniper instead vs USF, which slows down the arrival of PGs even more.