Blitz II is a massive World War II total conversion for C&C Generals: Zero Hour. You can fight as the Allies, Axis or the Soviets in the biggest World War II mod in existence.
German Panzer IVs defend a deep defensive line. While the T-34s cannot assault directly without taking heavy losses, by holding their position they force the PzIVs to remain in place simply by being there.
Can you destroy mines? I'm downloading the 3 hour thing right now.
Yeah, just run infantry over them and they'll disable them.