[dirtywick]

An Air bless will give your sacreds air shield which will reduce how often they get hit, maybe you could try to switch that Nature with Air (access to Air 4 with Kailasa isn't bad either, your pretender could cast Wind Guide and Flame Arrows too so it'd be pretty sweet to bring your pretender along)

Next, take a look at what kind of archers you're using. Markata archers have like no range, so they'll shoot at the closest thing they can. Atavi archers are better, they can reach the rear of the enemy army if you don't set up too far back and they don't set up too far back. Bandar archers have the furthest range, but are pretty expensive.

Take a look at your orders. What are the archers set to? Depending on what that is might be causing your casualties, if they're set to fire closest they'll shoot at whatever it is, even if there's only 1 guy and 100 of your guys. Setting them on just "Fire" with no specific orders tends to make them a little smarter, most of the time they'll switch targets, if there's something in their range, when your forces are in the way.

Also, the Bandar Warriors can soak up arrows pretty well. What you could do is put your sacreds on the flanks set to attack rear and the Bandar Warriors to attack nearest in the center so they'll take most of the arrow fire. Hold and attack on all of them though.