No. That would kill ISU. It already has a 200 penetration which isn't bad when think that it deals 240 damage and can switch shells to wipe infantry left and right plus it comes with martk target, guards with button and IL-2 bombs. I've plenty Elephants in 2v2 with combination of ISU+Mark Target+IL-2. You don't want to go head-on-head agasint Ele or JT. You need to be tricky.
Ok I guess I think it would be nice for allies to have a super heavy TD option on at least one faction even tho both axis do and the 152 would be easiest for that to happen to. Doctrinal of course. One that I can sit in the middle of most dota lane 2v2 maps where you can't flank and turn things into an allied shooting gallery like they can.