Wow, whom do we have here
Welcome to the forum.
And well, missile replenishment is NOT magical. It's completely realistic that archers, after a combat, went around the battlefield and carved out arrows from the bodies of enemies (on retrieved them from the ground)... however, right now situation is greatly simplified - for instance, you recover ammunition no matter if you win or lose, and 100% of it to boot.
The system I'd like to see in the full game would be like this:
Quivers and arrows would be separate, and arrows would be sold in big bundles that you cannot equip - only fill quivers with. (Like 100 arrows for prices that we have now. Btw, "whooping 25" for big quivers must be a bug.)
After a won fight, you'll automatically retrieve about 80% of ammunition you used (other would be broken or lost).
If you lose - must less (about 30%).
If you flee - no arrows will be recovered. If you have bundles of arrows of same kind you used up in your fight - they'll be automatically added into the quivers... after a message that you used up like 'insert number' arrows in a fight.
I think it's would be both realistic and fun.