Well, just get a secound quilver and the perk quick hands or whats it called. Found 20 arrows to be about enought in my game atm. With this you don’t have to check ot worry, your archer will simply stop shooting indicating that he is ready to swap new arrows. ;)
Same goes if you want multi role fighters, like having an xbow to fire at the start or a hook wo fight with when they stuck in the back row, perhaps a little spartan style jevelin throwing at the closing enemies.
You can even get the +2 slot perk to make an elite any scenario warrior.