I have some thoughts about arrows and archery that may be useful for the devs. Archery has two utilities: hunting and hurting people. And this become at some point very different and specialization fields.
Hunting arrows
Those were (and are today) specialized arrows designed to make big wounds. The target would bleed out causing a quick death. If the prey don't die instantly (often with large animals) it can run away, but it will be slower and leaving a trackable blood trail. This arrows are generally broad, serrated, with multiple blades, etc.
War arrows:
So, the main use of a hunting arrow is to provoke a big wound and kill rapidly the target. Isn't this what you also want in a combat scenario? Yep, pretty much. And those arrows will be as effective with a deer as with your mother in law. But, in war, a warrior would wear some protection, and the efficacy of a broad arrow will drop dramatically. This is why war arrows are smaller and tougher, so they can penetrate the armored target. Less superfice at the same force, means more penetration.The wound will be smaller, but a smaller wound may still incapacitate your enemy. What you want in war is remove your opponent of the battlefield. Killing him its a way to achive this, but not the main objetive. And deliver a small wound its better than deliver no wound at all.
Arrow making
Arrow making can be divided in three stages: shaft making, fletching and arrowhead making. The shaft is important because it needs to be straight and wood isn't always straight. Vapor it's used to make the material soft and bendable, then is straightened. Fletching it's one of the most important steps: is when the feathers are attached to the shaft. The feathers are why arrows can have a straight flight. In other words, feathers ARE the main reason why archery is useful. Arrowhead making is other completely different process. Arrowhead were made in a wide range of materials. Stone and bone were the first option in primitive eras. When bronze was available it was used a lot. Later, iron and steel were the preferred raw material. This mean that may or may not be done by the same crafter. Often arrowheads were made by completely different specialized worker, like a blacksmith. Finally everything is put together. Also headless arrows or blunt ones were used to hunt small game and to practice.
Conclusion
-Animals in general are very vulnerable to arrows. Only the size and the thickness of their skin gives they some protection.
-Humans are equally vulnerable to any arrow, at least he is using armor.
-In response to the above, you can find there are two main arrow types: "big wound" makers and penetration ones.
-Feathers are a sine qua non condition for effective archery.
-Arrow making its a complex process including an extensive set of skills and abilities.
-Is not necessary that just one person have the all the skills and abilities. Different crafters can participate in the the making.
-Arrowheads were made of a wide list of materials, including: stone, bone, bronze, steel.
-Arrowmaking, bowmaking and archery in general are hard highly specialized fields that require a lot of effort to dominate because the profit is equal: one arrow can bring food to a lot of people and one arow can stop a big menace.
Game implications and ideas
-It seems realistic that an animal runaway when its hurt by an arrow because was severely wounded. But being hit means that should have some implications:
1. The animal WILL NOT DESPAWN in at least 30 min even if nobody is in the area.
2. After a cooldown it should move at a slower pace because its wounds, maybe after a couple of secs, maybe after a few minutes. The time could be determined by the amount of damage caused by the hit. Even more, the animal could lose HP until it dies if the wound is big enough.
3. As it was recommended here, a wounded animal should leave a trackable trail. When you hit an animal it will leave a scent (like when committing a crime) that you can track. This mean that the devs can apply this without the need of think a new mechanic, you could use one that is already in the game.
This 3 things can improve the hunting mechanics a lot.
-It should be two types of arrows: hunting arrows and war arrows.
+Hunting arrow on a animal: The above listed effects.
+Hunting arrow on a character without armor: Pretty much a mortal hit. This arrows are made to destroy what it touches.
+Hunting arrow on a character with armor: no damage at all (like in legacy) o very little.
+War arrow on a animal: the same effects than a hunting arrow but with less damage, much less. It may be useful for hunting thick-skinned animals like mammoths (which should receive less damage from a hunting arrow).
+ War arrow on a character with/without armor: a considerable amount of damage.
-Bronze, iron and steel arrows should be a thing. The devs can make two new items: "War arrow" and "Hunting arrow" which require hard metal to be crafted. Those metallic arrows should only be capped by blacksmithing skills and abilities. You dont need to know anything about archery to make metallic arrowheads.
-Crafters use fletching devices so it may be used to craft de final arrow and to add some difficulty. Devs could add a kind of workbench that soft/hard cap the final arrow q.
-Feathers should be part of the recipe of all types arrows. Also, you dont need that much wood. An ideal recipe would be: 1 bone + 1 branch + 3/6 feathers. For a metallic arrow: 3/5 nuggets / arrowhead (a craftable item) + 1 branch + 3/6 feathers.
Summarizing, bow hunting would be more realistic and rewarding and bows can have some value in war or hostile situations but you need more skills and materials to achieve this.
So, well thats all, I hope that something here it's useful. If there is typos and errors, please pardon me, english is not my native language. What do people think about the topic?