Mob Damage Distribution

How does the damage done to monsters by an Aran attack change as the number of monsters hit increases?
Not awake atm, so iunno how to word this....

Edit:
Like how Heal's damage per monster decreases as the number hit increases, but the damage done to the mob as a whole increases...

I think the real question is, does it matter? If you hit 2 obviously the total damage you do will be higher than just hitting one, apart from the fact that you can hit 2 with your lower-end range and 1 with ur higher-en range (making this the statistic exception). Hitting more=more dmg, shouldn't that be enough? For me that is, at least.