Now try to kill a zis with Elefant and Pak with ISU.
Try using 2 M36 with AP around vs Elefant and see what happens, hell try using 3 Su-76 vs Elefant and see what happens.
If the support is tank or ATG its the same since weather 40 or 160 they still need only 1 shot.
Elfant is single purpose unit, it a slow tank destroyer design to win frontal engagement, attacking frontally and expecting to win is actually doing something wrong.
Try those units against a supported ele. These equal fuel/popcap match ups almost never happen, an ele is never alone. If it is its a player problem.
And where do you have the option to not engage an ele frontaly in this game? Almost nowhere. Big maps are 3 or 4 lanes with a few crossing options where you will run into the other players most likely. You can almost never flank in big games where ele's and isu's reighn. If flanking is a viable option you'd have a point.
The su76's wont have enough time to kill it, any support will kill them before they kill the ele with all their bouncing. Or the support draws the fire of the su76's also bouncing their shots.
The m36's wont fair better as the support will probably kill the m36,s before they finish off the ele.
The isu is under more threat then elephants are. Esp if ram gets gutted as intended The panther has more then decent chance to pen frontaly. It has a decent chance to bounce isu or other at fire. Its lots faster. And its also getting an unneeded and undeserved acc buff. Making it an even greater threat.
Now reduce isu ai range and it needs to expose itself to danger more often against supirior at fire power wich initself is already a bigger threat then allied at is to the elephant. It needs to have a decent chance to backoff if forced to be closer to the action.
Not everything is about units in a vacuum. The faction the unit is in matters as well. Its probably more important.
Coming back to hp left after 2 shot from ele and isu.
If the support is anything other the a tank or at gun. Say shrecks zooks ptrs and piats. The shreck will have a far greater chance off succes. Higher pen higher damage vs less hp left. The zook and ptrs do less damage have less pen vs higher remaining hp plus higher armour of those mediums.