Theres actually a historical record of M8 killing a Tiger, from behind at very close range

It must been like 30 meters of range if I remember correctly.
What comes to details, if I remember correctly again... it's so long time I read the account.. there was no real penetrations, but some of the hits caused something to dislocate, which caused a fire in the engine and thereby loss of the tank.
However killing Tiger with the 37mm pop gun would be more of a luck than a rule.
I wonder how HTC has modelled penetration for the guns.
If HTC used historical test data and from US & German sources and didn't take differences in the test methods into count, then there can be some errors.
Like yanks were happy if they saw a 'light through the crack', while germans expected full penetration.