Regardless of your teammate. Say you see a king tiger get called in. What do you as a USF player start building? How do you maneuver? How do you exploit a king tigers weaknesses in general?
It's not like teammates can always be relied on on randoms.
In the same way you do it in 1v1, p47 for support, swarm with M10s, use jacksons on the front at max range + path block the kt with EZ8s or normal shermans, use arty on it/it's retreat path if you damage the engine, ambush it with zooks etc, each commander has it's perks to deal with it, some more than others.
The most common tactic is still to pathblock it with a medium that can take 2-3 AT guns shots while you have your AT guns/tank destroyers on the front at max range finishing it off without risking anything.
Or if you can trade vehicles effectively (mostly in the m10 case) you can YOLO rush it to finish it off and be sure that it dies with jacksons on the flanks/behind, but It's generally something you shouldn't do as they easily die against schrecks/at guns.