KV8 vs cas is a bad choice. Three squads of pg with shreks killing it with few shots. Don't forget about at strafe that wipes tanks.
AT strafe is dodgeable and requires LOS which means its likely in combat and moving around already. Its not much of an issue with the KV8. Shreks need to get close enough to the KV8 to shoot and must stop moving to shoot. This means you can keep your tank out of range of the shreks whilst still burning them (this is known as kiting). Pgren loses 2 men and retreats, you chase him all the way back to his base burning his Pgrens and the rest of his army.
BTW,(340mp + 120munitions)*3 =
1020 Mp + 360 munitions. A KV8 costs
390mp + 145 fuel. If he doesnt spend munitions on teller mines you will force him off the map within minutes with the KV8.
Teller + AT strafe will do the trick but that can be fairly easily prevented with sweepers because if the axis can have sweepers paired with every squad to prevent demos, then so can the soviets to prevent tellers.