I also tend to use copper arrows for military purpose, but I have to disagree with the bone ones.
If you are not short on wood, wood and bone arrows are very similar in damage, but bone ones come in very small stacks.
It is OK for legendary hunters or training (either on live targets or when it works on target practice), but early hunters would often not kill their prey in 5 shots, making them cancel and come back to fetch an other 5.
An other thing I tend to do later on is to use ironwood or steeloak to make iron/steel grade wooden arrows, but that's only when I have enough bars of the respective metal.
It is slightly better than 'normal' metal arrows, because it doesn't require fuel to make (as humans often don't have a good access to lava).
Also, not sure if it can help you, but I tend to make a 3-4 squad for my archers (rather than hunters), and put them with an order that is "At least 1" and "Station", targeted on a guard tower above my entrance.
That way, there will be someone ready to shoot any hostile without delays.
I let the other train normally, to gain the other skills (shield/armour, mostly).
All in all, it all comes down to your specific fort, but most human forts gain access to quite a vast amount of copper early on (with the quarry digging), and appart from very early military, weapon traps or training your smith(s), there are not many uses for it.