yes that's possible.
you take the bundle with the arrows.
hold down the ctrl key.
then you get a window when you want to drop down the arrows on the ground.
select a number of arrows ex 45 on the window and that amount is dropped on the ground.
give this to the deathknight.
but don't dubble click on the pile on the ground , because then the arrows both combine toghetter again.
i didn't tested this out by dropping the arrows to the icon of the deatrhknight and then press ctrl.
but i think thi swould work too.