As you can guess, i want say about ISU-152. I understand what concept have this assault gun in game. But its bad concept. You turned best antitank machine to antipersonel, that can be worst thing what you ever did. Now its unuseful expensive trash but it can be one of the best allies tank destroyer.
I think need just delete switching armor-piercing and high-explosive shell (this tank must use only high-explosive) and give him damage like jagdtiger and not always but frequent penetrations . Also it can have light armor to fit in soviet concept