The fact that you included king Tigers shows how for off the mark you are. It was mostly a failure due to its singular unreliability and difficulty to transport and maneuver. And it was made in such low numbers that it’s barely worth mentioning.
If you did more thorough research you would discover I am on the mark.
Although made in low numbers where deployed they were effective. Here is a link to just ONE service record concerning the Tiger II.
http://www.achtungpanzer.com/gen10.htm