What I said in the Soviet thread fits here as well, since we are now talking about the Elefant and the ISU-152 and their respective positions in each Army.
The Elefant and Jagdtiger are heavy casemate tank destroyers with 110 Rear Armor and 1040HP, the SU-85 cannot challenge them because it is woefully outranged and outgunned, so they must flank it with T-34-76 but this is not successful either because the immense HP and occasional bouncing mean that you could leave it idle and alone and it'll take a pair of T-34-76's twenty seconds to kill it.
Unlike facing the ISU-152, the Soviets don't have a Panther they can send forth to poke holes in the front or front sides without risking swift annihilation. An Elefant does 300 damage, so a shot to an SU-85 that dare challenge it will put it down to 340HP in a single counter-hit. An ISU does 240 damage, so if a Panther steps up to challenge it, a successful counter-hit will only put it down to 720.
It is very difficult for stock Soviet to deal with an Elefant that is completely unsupported, add in the fact that it absolutely will be supported and you've got something that is incredibly difficult or even outright impossible to remove. On the other hand, Ostheer and OKW both have a tank that can not only take a few hits to the face, but dish some out.
Let's pretend Axis can only field Panzer IV's and have to deal with an ISU-152. You still have a much easier time than the T-34-76 v Elefant: Panzer IV's higher penetration allows them to punch through the ISU's weaker rear armor 100% of the time from max range, while a T-34-76 is required to close in to medium-close range for a 100% chance to penetrate an Elefant from the back. Now factor in that the Panzer IV has blitz, and it is extremely easy to rush around the side of an ISU even if it starts reversing. But Ostheer/OKW doesn't even have to do this, because they have the Panther.
Soviets do not get that choice, and they still have it considerable harder. Had the Soviet's medium tank been the T-34-85 I would understand, but it's not. Lowering the ISU-152's rear armor to Elefant's does not level the playing field, it unbalances it. Here is statistical proof:
Panzer IV vs ISU-152 (Live)
125/115/110 Pen vs 155 Armor = 80%/74%/70% chance to penetrate.
T-34-76 vs Elefant/Jagdtiger
120/100/80 Pen vs 110 Armor = 109%/90%/72% chance to penetrate.
Panzer IV vs ISU-152 (Preview)
125/115/110 Pen vs 110 Armor = 113%/104%/100% chance to penetrate.
Now consider Axis also have access to Panzerschrecks which they could support their Panther or Panzer IV rush with, and you're dealing damage to the ISU at a rate far exceeding what a T-34-76 rush could do to an Elefant or Jagdtiger.