I think I cut the marder sight bonus from 20 down to 5.. don't recall exactly. It'd require someone to test it. I know I removed the damage bonus against M10s and Shermans.
Those were all balance-playtest changes.
If you implemented the beta changes then the marder gets only 5 sight bonus from locking down aye.
It should probably lose a pop cost and maybe 20 fuel if the sight bonus is gone though. Because it will be a significant nerf and the marder balanced decently atm.
Marder lost sight range an in addition it also lost the damage bonus versus shermans, think there was more but I can't remember off the top of my head.
As of current version marder still has sight bonus.
The damage bonus vs shermans had to go, which is fine since it got a cost decrease in the process.