I have actually made my own arrows from scratch in real life. It still depends massively on craftsmanship, but the shock on impact really is tremendous to the point where it can break at multiple points. The arrow tip is one (even metal arrowheads can fracture and flatten), the notch that it rests in can split and fracture the shaft like an axe head through a log and the fins can come off passing the bowstave. I'm actually surprised a projectile impacting so much energy is able to be recovered at all.
Game balance is totally different and I understand, but for those who had questions, an arrow hitting something is much more violent than it can seem. Especially one homemade.