So, now we are Miles away from your basic question.
Nope, it was a Mix of 8th Batch Hulls and 1st - 3rd Batch Turrets.
We´re talking about Mid 80´s Leop 2, didn´t we ? We are talking about Chobham Armor, didn´t we ?
So talking of penetration in a "LOS- thickness" is nonsens. Chobham works other ways!
The Need for a "Mannheimer Konfiguration" was given by the use of New KE Projectiles. But this was at Mid 90´s, so Year´s after what you are questioning for.
Only way to improve a existing Turret is to change used Materials or to saddle it up, as A5..