I guess I may have been just a little influenced by a Redwings v Cruzz game the other day where an SU76 penetrated every single shot at a Panthers front from medium range and killed it.
Those are still good stats though.
frankly those numbers are higher then i remembered and i would consider them reliable (>50% pen chance) but the zis at least needs to have those pen numbers and the su-76 is doing 120 damage so it's not as much a threat. the su-76 might need a small cost increase but i don't think any of the other stats should be touched.
i think a big part of the problem is how armour/pen interact in this game. currently the system heavily favours weapons as a weapon can, practically speaking, always pen, even if the chance is very small. a weapon with more pen than the armour it's shooting will always pen but as long as it has more than 3% (iirc) can still pen. personally, i'd prefer a system where weapons had a 50% chance to pen against an armour value equal to the pen value and then 100% chance and 0% chance at two equidistant numbers, say 100% chance at 50 armour, 50% against 100 armour, and 0% against 150 armour.