So if you drag one armor item onto the equipment that has the slots it will put one into the first slot.
But if you try to drag a second armor item of the same type onto the same armor slotted item it will stack 2 on top of each other.
But not give the bonus of the second armor item.
So you have to click the armor slotted item and sort the armor items by 1 and put them in each one at a time.
Just makes doing lots of sets a bit more tedious.
Would it be possible to limit the stack amount in armor slotted items to just 1 for each slot so it's easier to gear them up?