Most AT options doesn't translate to best AT options though. Sturm Shrecks are god-awful, and it's extremely rare to see good players use them.
Raks are honestly useable only because of the cloaking gimmick, but have pathetic range, a hyper-exposed crew, and simply atrocious stats for an anti-tank gun. I hate facing cloaked AT guns as much as the next dude, but when playing OKW I really wish I could just have a PAK40. Raks get outranged by Allied TDs, and die so often because they're 10 range closer than every other AT gun. It's a weird, cheesy, unit that performs poorly in its intended role and overperforms in situations where you can abuse its awkward mechanics. Also, you're emphasising "T0" rak like it's an actual benefit. T0 rak is to make the game actually playable. You've conveniently forgotten that no Allied faction needs to face UC/Clown Car - if they did, they would be wiped off the map in 5 mins unless they got T0 AT as well.
Puma and JP4 are both great vs mediums, but both suffer from having very low pen. Design-wise, Allies generally don't have much heavy armour, so the Axis repertoire naturally didn't include many units with high penetration. This actually makes it very difficult for OKW to deal with heavy armour - and it's why Spec Ops is so insanely good. It gives a legit Pershing/IS2 counter to match those heavy call-ins. If you don't go Spec Ops, T4 + Panther costs will require too much fuel, and the IS2 call-in with 375 armour will steamroll your low pen AT options. Having the most AT options doesn't mean much when none of them have even 200 pen. To get a stock Panther out vs the IS2 requires the OKW player to have approximately a 100 fuel lead, and even then a Panther can't brute-force its way to a win vs the IS2, since it gets badly demolished in a straight-up brawl with the IS2.
The three Allied factions all have a 60 range AT gun and a 60 range 220++ penetration tank destroyer each, which they need because Axis vehicles have more armour. The OKW AT department is very comfortable vs medium armour but generally struggles vs heavy armour, and the Panther's shorter range makes it easily zoned out by AT gun walls.
One of the few situations where I'd say ulu is making a valid point, and I agree with him on this issue. The reason most players don't notice this issue is because Spec Ops covers for this OKW weakness perfectly, and the CP5 has OP sight range so it feels as if OKW doesn't have any anti-tank issues. If we nerfed CP5, the faction would easily be overwhelmed by Pershing and IS2 call-ins.
OKW is designed with their income penalty in mind. They are designed to be able to counter enemy armour no matter their fuel income. Of course they can't face down the hardest allied target with ease, that's literally the point of that tank. Allies have higher pen TDs because Axis have a NUMBER of high armour targets in their core roster. Across all the allies only the brits hammer and anvil tiers have stock units over 200 armour. That's 2 units that are mutually exclusive across 3 factions.... Okw has 4 by themselves. 1 faction has double the high armored units than the 3 opposing factions combined.. Of course the other side has higher pen TDs.
Shrek on sturms was never designed to be. It was only put there because a Rak, a puma, a 60 range TD and a panther were simply not enough AT for the masses. I don't like the Shrek on sturms and I don't use the Shrek on sturms, but that doesn't mean it's not an option if need be. Against the Is-2 one shouldn't be expecting a single unit to be countering it like one shouldn't expect a single unit to counter the KT (this is a reason I think the KT is UP, and have in the past requested its armour bump to at least 400)
Rear armour on all heavy armour was dropped also, so flanking is always an option (another reason the slow ass KT should have its armour upped)
OKW isn't helpless but everyone wants the best way to do things to be frontal assault. Heavy tanks are supposed to dissuade that. Allied TDs have been overbuffed to bypass that but that's a symptom of a shitty pen system that means even a final tier TD could likley do nothing at all against a number of units it was designed to counter. Add deflection damage to all high end TDs and drop their pen so armour can be a thing again.