Some gameplay questions and a couple not

[Smersh]

When a vehicle is hit I get some numbers. What exactly do they mean? For example PEN 39, Arm 32 @54 degrees from a Leopard 1A5GR2 hitting but not killing a Type 59 tank.

It's fairly simple. PEN 39 means penetration 39cm, and Arm 32 means the thickness of the object being hit 32cm. @54 degrees, means hitting at 54 degrees.

When the PEN number is above the ARM value and doesn't result in a kill, it means that the round penetrated but did not destroy the vehicle or something similiar. Usually this also results in some system on vehicle being damaged.