Penetration power of German 2cm guns

[BigDuke66]

I recently checked a different game for the penetration power of the 2cm guns and found that it was rated rather high, there the German 2cm is rated with 3 while the 3,7cm has 4.
I thought I check here too and the usual value here is 4 for the 2cm while the 3,7cm has 5.

The penetration performance one can find on the web for the 2cm is about half(and less on higher ranges) of that of the 3,7cm, so one would expect a value of maybe 2-3 here in SP while about 2 in the other game, but both games rate the German 2cm much higher.
The question is, what is so special about the German 2cm that I obviously miss?

[DRG]

PzGr.40 (Armour Piercing Composite Rigid) can penetrate 40 mm of armour at 100 meters and that is based on rolled homogenous steel armour plate set at a 30° from the vertical. Our numbers are based on the best performance possible and we try to use numbers based on full vertical armour pens but stats from guns vary on testing practice which makes the entire process a bit of a guessing game at times. The pen then drops off the further to has to go based partially on the WH size and by range which is shown by the AP calc included with the game and the armour slope calc so 40mm of 30 degrees sloped armour is 46 mm of vertical armour. PLUS you will ALWAYS be able to find variations in pen stats between sources if you dig long enough.

The source I just used also says at 500 meters it will pen 20 mm of armour which is exactly what our AP pen calc says it will in the game with a "best" AP pen of 4.

[Mobhack]

Thread moved to the correct sub-forum. OOB issues are discussed in the TO&E forum.

Regarding "best" figure in the AP calculator - each "bucket" shows the best sample of 1000 "shots" so it could be a 1 in 1000 occurrence, the default is an averaged value and is more reliable.