The arrows in wars can stay, but how about adding a way for the attacker to have a chance to block some of the damage. For instance, when the arrows are about to fire three shield silhouettes will appear a top of each person in your group. A bar will then go across the screen and you have till the bar finishes to tap as many shields as you can.
If you get one shield it will block 25% of the damage. If two then 50%. If you manage to get all three shields on a character it will then reflect all damage back to the opposing side of the same color. Similar to the events.