But then you completely nerf them at vet0. I though you should give them same accuraccy as other PTRS have but decrease their DMG to 10 so they are less RNG based, vet based but still are only half as good as other PTRSes
Fully agreed with this, giving them low damage and high accuracy puts a hard limit on DPS by nullifying the accuracy boost. If you do that, their veterancy will cause them to hit 100% accuracy, which will act as a hard-cap on their DPS due to low damage per-hit.
that's why Stug could make a role of assault gun, being good vs tanks and infantry and not being good only vs one type of unit and even tho its tank destroyer, it's not that good in its role, simply to slow to rotate and easy to outflank
They did that before, and all it did was eat into the Panzer IV's role while not being particularly good at anything. It was the unit you bought when you were in a pinch and couldn't afford a Panzer IV. The current role is best because it brings balance to Ostheer T3, which looks like:
Panzer IV: Generalist
Ostwind: AI Specialist
StuG III: AT Specialist