I was wondering if i have 3 starpriests in one list and give their staff ability to the same units three times the dmg output of the units would go (((2xDMG)2xDMG)2xDMG)= 8x Starting DMG???? if they roll a 6+ to wound??
It doesn't stack. Take a look at the wording, it says: "twice the normal amount of damage" Normal means: the number on the warscroll.