That been said, not sure what units you could adjust besides Penals.
T-70 could definitely do with a nerf to killing power on retreats, possibly even a slight nerf to killing power in general. The T-70 is just massacring infantry left and right and imo it's way good. With its sight bonusses it even has purpose into the mid/late game, and Soviets have good AI squads so there is no need for it to be this devastating.
I think the current Luchs is the standard for a good light tank: proper shock value, good damage over time and powerful enough to push unprotected squads off the field but not as deadly and can only wipe when squads retreat dangerously late. A unit that synergises well with infantry but isn't as devastating on its own.
Nerfing the T-70 a bit would also mean the Mobile Defense / Puma meta could tone down as Ostheer wouldn't be as helpless without the mobile AT. It got boring real fast seeing modef picked almost every game.