Shin is a smithing maniac who doesn't know what "overdo" is and it's fair for her to scold him for that. the bow is probably so strong it needs too much mana too
@degenerateafro - I know for sure as a guy using a 60# Recurve that protective gear isn't just for aesthetics. While I don't have a need for a chest protector, I learned the hard way about using a forearm guard. Thankfully it was when I was younger (22) and using a 40#. Normally a person might just get some painful welts, which happened to me as well. However, I kept putting off buying one -- for no particular reason, really. Then one day as I was shooting in the woods while camping I had an arrow break during release. The broken part of the arrow left a nasty cut below my wrist, and because of the misfire, the bowstring tore off a large piece of flesh on my forearm; in between the middle and my elbow. Needless to say, after the hospital visit I didn't hesitate to buy one anymore.
I kind of just give it all a pass when it's in fiction like this, but I also think many people really underestimate just how powerful a bow is. Which is also, probably, because of their depiction in stories as well.