Paks are not useless vs tanks. Like I said if they can be pretty decent, but they don't have survivablity. Shreks are great on squads with oorah, body armor, and six men. Especially when you are fighting tanks with low anti infantry capability. Turn that around and you are using them with 4 man squads , fighting armor that can wipe them before they get a second salvo off. Shreks are the best at in the game, for Soviets.
Sorry mate, but sometimes when I read your posts I have the feeling we play different game. You can say a lot about Germans but not that they're lacking anti tank capabilities.