look, we have tested this out, lost lots of exp trying, it is EXACTLY the same AI as Hornets. if you are too far for a hornet to melee you, it will range you, and it will continue ranging you until one of you dies. If you tank attack a hornet it will melee you for like 20 times harder than the ranged attack.
No need to foolishly throw away exp on servants, if you don't believe me, go find the hornets. They will kill you if you let them but they are good practice, so off now test away.