Archers... my favourite unit type in most games

Just will just be a start, my intention is to make this as realistic as gaming sanity allows
arrowsQuivers could carry around 20 - 25 arrows, although in war, archers would often not carry a quiver at all, because arrows would be supplied at the start of a fight and they would put them in the ground, which allows them to fire faster.
On average, these 20 - 25 arrows would be fired up in about 2 - 2 1/2 minutes. (Times vary with experience and training.) At the point that these arrows were gone, they'd not need rest already, being trained for war.
During a battle it would mean that arrows would need to be resupplied constantly, either in quivers, or in heaps. Or all would just be supplied with more arrows.
Ah, here is something:
Henry had approximately 5,000 archers at Agincourt, and a stock of about 400,000 arrows. Each archer could shoot about ten arrows a minute, so the army only had enough ammunition for about eight minutes of shooting at maximum fire power. However, this fire power would have been devastating. Fifty thousand arrows a minute - over 800 a second - would have hissed down on the French cavalry, killing hundreds of men a minute and wounding many more.
Each archer would have been shooting 80 arrows during that battle. I can't imagine them having that many ready at start, so the battle would have lasted longer than these 8 minutes, but it shows the stamina is going to let them last longer than 1 quiver anyway.
Regaining arrows over idle time is a nice idea, but it wouldn't cover the use of 1 quiver per battle. Either we increase the number of carried arrows (2 or 3 quivers), or we go for the fatigue. Personally, I'd prefer the first option.
The number of arrows of 3 quivers would be what would be supplied to them during battle, perhaps they would have a small resting time after each 25 arrows, to represent the switching of quivers.
Your idea of regaining arrows over time is good. I can't imagine that professional archers wouldn't know how to make their own arrows. The barracks would always have a ready supply of arrows (well, not always, but let's forget about that), which would allow archers to resupply instantly.
Another source for arrows would be the battlefield itself. Fallen archers (from the same type) would leave useable arrows behind, as well as the fired arrows that missed their target and are still useable. With both sources, there would be a randomisation on how many of the arrows would still be useable.
That would be all I can think of now... for arrows.
Spread of fireArchers were used in numbers, their accuracy wouldn't be to write home about, but with the number of arrows shot at a time, that would not really matter all that much. So the arrows should indeed be spread, but still hit
a target.
What I would like to see is that arrows would not be directed at an enemy, but given a calculated curve when shot. The arrow would follow it's curve and only hit if an object would be in it's path. Wether that object would be a tree, rock, enemy or ally, etc.
Such a shower as a battalion archers could produce, would be death for unarmored and light armored enemies, but for heavy armored opponents, it would hardly kill anyone. If I recall correctly, it would take an average of 3 to 4 arrows to take down a soldier. It didn't say what kind of armor such a soldier would wear, but I take it that would be light armor.
It should also be noted that archers were a bane for horses too, forcing cavalry to turn and retreat or continue on foot.
An arrow wouldn't kill a horse, and they could be armored too you might say, but one arrow is enough to make a horse uncontrolable, which is the reason that against archers, footman were preferred.
There is more, but I got to go.
Solinx