This isn't Men of War; realism takes a back seat in favour of balance. The ISU would become very overpowered if it was able to kill ANYTHING it came across, it needs some counterability. If somebody wanted a defence and infantry clearing tank they should have picked the Urban Combat doctrine. It already has a deathly slow reload time... any slower it wouldn't be worth having having in the game at all.Also, 'Rarely used in a Tank killing role'? Where the do you think it got the name 'Beast Killer'? Certainly not from destroying buildings.
Between November 1943 and May 1945, 1,885 ISU-152s were built. Mass production ceased in 1947, with 3,242 vehicles produced in total. : wow, not so rare then, is it ? Compare it, say, to KT or JT
thought it was "feline killer" or something like that