To kind of add to Vaz on this topic there is really no reason to not take marks on your units as they are just to good to not take. If the reason you don't want to use them is because you are worried about being limited to a specific colour scheme then put that idea aside. You can paint your army however you want and marks can be shown easily with just using banner bitz in the god shape or just telling your opponent beforehand what unit has what mark. My WoC army is not painted after any particular 'god theme' either as I don't like being limited to how I want to paint them up.