Monsta has not really played STW2 as much as he would of liked but he will try and help.

First off and it may seem silly but are you using your loose formation?

Second...Monsta often find the defned who fires when the enemy comes into range often hits first thus gains advantage..sometimes moving into range or click to target enemy you lose the first shot. Monsta thinks first shot is important and it is fired by the whole unit not like first shot of second firing players because they have taken hits thus their reply is weaker. This may not be right for this game but Monsta found this to be true before.

Monsta has also read sometimes units miss a firing round due to bug but again not sure on that.

Monsta has noticed also that archers when being given the order to fire at certain unit will stray closer than their max range thus also taking damage from enemy wait before they let off.

Out of interest try adding a CA (cav archer)..then if you equal 3v3 (for example) in the arrows battle you can pressure from flank on valued units such as monks with CA..this means enemy either loses monks (which he wont want to) or turn one of his archers to try and destroy your CA, If he turns his archers on your CA then you gain advantage by either now using your spare archer to hit his valued troops or kill the unit he has turned to face the CA or double up on one unit etc.

This is basic knowledge and may not be helpful but it may help somebody.