Thralls not using equipped weapons, still not attacking enemies

[roro4066]

@RaderBad

1. Equip a thrall with a weapon similar but of better quality than what they came with.
   Example A: Archer comes with Ancient Bow equip with a Star Metal bow and dragon bone arrows.
   Don’t forget to drag the dragon bone arrows on to the bow to choose ammunition.
   Example B: Sword and Shield replace with a higher level sword and shield.

Moral: Do not try and change a spear thrall into a sword thrall.

To make sure they know to use the weapon put it in their hand.
I noticed it takes a couple drag and drops to get some of the weapons into the proper hand.

you should have a look a this thread, Here is some feedback about thralls mechanics
because you are assuming things that many players do assume too, but these things are actually only rumors. And this thread main purpose was to bring light upon those rumors.
Constantine is right.