Armour damage model

[ECV56_Guevara]

Wiith a squadie we were wondring if armor damage model was chenged in 4.12
A few questions:
Atacking Tigers with 37 mm seems to be harder (obviously from rear, motor and back turret side) Anyone could destroy a tiger I or II with this gun?
Is the damage cumulative? I mean wiht several impacts, could it be destroyed a few more rounds?
The same impression atacking T34/85 with stuka G1. Couldn t destroy it with lateral impacts. I can t remember if this was doable before.