PGrens are fine, learn how to use them.
How do you "use" them properly when 1 shell with out warning will instantly kill your squad, and were not talking about a 120 or howitzer shell, we talking a 82 mortar shell or Scott shell. They are very fragile and expensive.
Loosing to IS2 is L2P issue most of the time. IS2 is not OMGWTFWUUUTGARDENYOURELIC unit. There are many useful commanders against IS2. My best is 9 secs to kill IS2 without Tiger or Elephnat. Bad Pak43 commanders? The one with Pak43, Command Pz4, smoke, railway arty is one of the best. Thanks to this commander I was able to kill IS2 in less than 10 secs.
Tiger + 2xPak40 is a killer against IS2. You dont have to even use your Tiger against it. Focus on support while Paks get veterancy, stun and finish.
Tiger + JU strike
Two very good doctrines with Elephant.
Countless with Tiger.
3 (I guess) with Pak43, one of them is great, two are decent.
And you are saying that Ost has no counter to IS2 except Elephant..
Losing to an IS2 is not a L2P issue, in every stat except ROF the IS2 wins out over the Tiger. The Pak40 can be easily 1 shot by the IS2, infact there isn't a single Ostheer MP based AT unit that isn't shot by a IS2 unless it misses.
And the pak43 is in a fairly shit commander, Command Pz4 is a waste of fuel unless you are floating a shitload (which you shouldn't), smoke is good, hull down it situational, and rail away artillery is a giant waste of munitions in an already munition starved faction.
The elefant is excellent, and comes with 2 good doctrines, Tiger comes with a few good ones (but in the current medium and IS2 spam meta Elefant will always get you more bang for your buck), and every Pak43 commander for Ostheer is just not viable in the current meta.
The Pak43 works for OKW because OKW is based around forward bases and entrenching, Ostheer really can't afford to do that as much with how fragile bunkers are and how expensive the upgrades area.
Ostheer has no reliable counter to IS2 spam except the Elefant, because the fragility of Ostheer infantry and AT weapons. The elefant is mobile (enough) and can take a few shots to the front. The elefant also does well versus medium armor spam, while a Tiger won't get you very far before it's force back again and again.
I dont see a big issue in ostheer. The only major thing that comes to mind really is the T1 lieut vehicles of USF that put on so much pressure on to you its very hard to maintain map control, other than that its mostly fine. In 1v1 it depends alot on the maps.
The DPS in games above 2's gets so high that Ostheer basically becomes a support faction for OKW, just making fuel caches and calling in fuel drops due to the fact instead of 1 horde of riflemen and shocks it's 2 or 3 or god knows 4 hordes of shocks and rifles.