If you can circle strafe an ISU with 2 stugs then you are playing against someone that has no idea how to properly support his units.
The Elefant is completely beside the point of this discussion. I haven't played with, or against, the Elefant enough to comment. Start a thread called "Elefant" if you think the Elefant is a problem. This thread is about the ISU.
As for the Brummbar, there is a world of difference between 40 range and 100 range. 40 range puts you face-to-face with an AT gun; 100 range does not. And I've never seen a Brummbar 1-shot a Zis squad. Video please?
Again, I think it was Shazz who said it best: great AI, great AT, extreme range--pick two. (The Elefant that everyone keeps complaining about in this thread only has two, as does the Tiger).
I'm not saying it's viable to circlestrafe an ISU-152 with stugs. I just said i have done it. If you can get some stugs with vet 1 in close range, then its pretty good.
Keep in mind that ISU-152 costs 720 manpower, so unless it wipes 3 squads it stills hasn't payed for its cost, also 260 fuel.
For the same amount of fuel you can get a panther provided you have t3 up. (It's very unlikely that hes not going to get say a t-34 or an su-85 before he gets an ISU-152).
That said, the squad wipes need to be toned down. Maybe make it less effective over range?