@Markr and Lunar: Sure you have fair points still i dont know what exactly sandbags do.
It's already been said - they add HP and slightly lower penetration chance
In my last games i didnt used them and shermans still stood 2 schrecks sometimes.
That's because of the random factor.
The accleration reduction and overall lowered flexibility is already in game when sandbags are upgraded.
they become somewhat slower but that doesn't make them easier to hit while moving so it only affects the movement speed itself. Maybe it takes a bit longer to get out of artied area but if you keep them away from each other, then using barrage on one sherman is kinda waste. So I have to keep my stand point that these upgrades increase their survivability (e.g. increases quality) while not affect the quantity factor.
Still iirc the chance for Tank IV to pen e8 or at least normal 76 sherman using standard AP rounds is still twice as high as the chance of the sherman to pen the tank IV using also basic AP.
Maybe in the basic stats but since the E8 is used as the main battle tank, people usually put TCs in them and those increase penetration (but Axis players usually use TCs with big cats) so in the end you quite often end up with better (or maybe same) penetration chance in case of Sherman vs PIV.
Bottom line is that it still feels off :/.