What has not been said here: medieval arrow quality in terms of accuracy. Accuracy? The most critical part to me.
I suspect it rarely met nowadays arrows quality.
Arrows of the past are hard to study as wood turns to dust quickly and arrows making isn't the most prestigious technique to write about(never heard of, maybe some info exists).
Variable arrow quality impacting it's characteristics seemed to be critical in medieval armies in lasting "raids/campains/wars". Archers tryed to get their arrows back from the battlafield (random arrow characteristics and flight path guaranteed), archers try to make their own arrows (scary quality). On the other hand, bows were often used by hundreds against hundreds and often doesn't need to kill anyone to be useful, accuracy isn't a priority in that case.
I'm an archer IRL. Due to the country i live in, once we've bought cheap wooden industrial arrows. Like thirty.
We spent like 10 minuts choosing every arrow.
We fired at 10 meters, 20 meters and 30 meters at a piece of cardboard 60х50 centimeters maybe with smaller drawings on it.
Before that i only fired carbon/aluminium arrows designed for shooting at fake animals and other sport aims.
These sporty arrows flew streight and rarely had any kind of deviating behavior. In several years of flight & hit, few deformation/damage appeared.
Wooden, carefuly choosen cheap(<key moment) arrows trajectories were different on the first flight at 10 meters.... Let you imagine what happened after few shots and at increasing distance... Slowly, most of the arrows started to have their own personality and behavior...
We started having our champion arrows, that had a sooo bad flight path that we were joking about how and where it's gonna land lol. These arrows didn't allow to hit precisely even after around 15 meters...
After a month of shooting, hitting stones, trees, various trash we fire at - arrows that survived (many broke, some lost) became completely inadequat. Not speaking about humidity impact (not a humid air here), rain, bad treatement in general...
I suspect medieval arrows, even those not mass produced, rarely allowed to hit a single target with 100%. Too much random. Skill is useless when the arrow path is unpredictable after 15/20/30 meters.
Means a good probability of missing a standing person in a field. Not speaking of zombies in dark corridors that rush you with some trash in hand! Balls of steel required IRL, maybe even ingame =)
An exception would be arrows of advanced quality for non common warrior. Like elite warrior class, nobles, etc. Still doesn't mean 100% arrow accuracy.
Had to share this experience, hope it's useful =)
PS: Lots of "Edit" trying to polish my english x)