I know, but this is not really playable. They are fit for fight again after 1D10 rounds. As they don't have any health or Endurance they are impossible to defeat. Your only option is to run away. Or have a flamethrower with you. As a GM I don't allow heavy weapons as it seems quite ridiculous for a group of players to have a Flamer just in case.
Ok, it is good if the PCs have to choose between escaping or dying from time to time, but not everytime they meet something that could be classified as a Zombie.