kv-1 is a bit OT but more about desing and less about raw stats, it just needs less rear armor and more speed (to medium tank lvl)
kv2 need a rework
and isu 152 should be brought in line with the jagdT and ele rear armor changes
so he is right
KV-1 is pretty weak, I would give it UT at best in the scale of this thread. Yeah, it has high rear armour, but without it, it would be completely useless. So there is that. Even now there is little point of building it. The only reason why it sees any action is becouse it has been put in one commander with newly overbuffed IL-2.
KV-2 doesn't need rework as a singular unit. The whole commander needs it. As it stands now, KV-2 is not worth its price for how late it comes and how easy it is to counter. Would give it UP in the scale.
ISU-152 is not in the same class of units as jagd and ele any more. Sure, when supported it can be worth its price, though only on the most favourable maps (that are also unfavourable 95% of other soviet units) It definitely doesn't need any nerfs to its armour, especially taking into consideration how quickly it dies when attacked from the front by TDs. In the scale I would give it 'ballanced', with additional description 'situational'.