Please define which side are you talking about. German tank hunters are useful throughout the war, the Soviets only once they get the RPG43-AT grenades. And even then, they might still be armed with bare crappy molotovs.
Set your tank hunter teams to ambush enemy vehicles that pass near their location; do not try to charge in the open after the tanks, unless the location is extremely secluded, and the target is slow.
The grogs will fill you in on the rest.