We already have wet stowage vehicles in game. It’s all the 76mm Shermans.
Those dont have wet stowage ingame, they have the ammo racks in the correct places, but they are just normal ammo racks with none of the added armour that wet ammo stowage offered.
While wet ammo stowage did not work as intended, it was still able to absorb shrapnel at least one time without detonating the ammo.
I can’t say no to more M4s! Hopefully this one can stay at rank 3.