asymmetric design in regards to the range difference was unlike in the days of super range su85 with the 10% bulletin. Making them all equal would also solve the issue. On lane maps both sides would have to weigh how to push with the long range TD's instead of the slow creep of a JT/Ele that is the usual degrading. Even if it means making the ammo type of the isu-152 purely AT.
I believe the reason it cannot be equal is due to the fact mark target exists. It would simply be to easy to combo that with a teammate and out damage the JT or Elephant