Archer AI should include the ability to recognise when to retreat from an attacking enemy. This would be
when being targeted by melee enemies and having nearby friendly melee classes
All other situations would have the archer stand and fight with a knife (if their morale holds up), rather than lead the enemy around in an awkward, ai driven kiting match, and even potentially leading enemies into vulnerable areas. Also, the player should not be rewarded for sending an unsupported archer against a strong melee enemy by having the archer be able to run away from slow enemies.
One AI ability that i would love to see but only dear to dream would happen is an archer AI smart enough to seek cover. This could possibly be done by searching for 1 high or 2 high blocks that the archer can put between themselves and a ranged type enemy they are targeting. some extra animation for crouching or peeking out from behind 3 high block structures would be fantastic for archers.
Graphically, there should be arrow trails that can be seen from afar when the archer shoots arrows, like those you see in total war games or such like.