So re-watching the video the OP posts and the video rafykoby posted I have a theory which will require some testing. You notice how in both videos the target they are aiming is at uncharacteristically motionless (i can't speak for the first target in the OP video due to how fast it was)? Neither one of them seem to be running their given scripts when the shots are fired. I went to a random camp and started sniping and only half the mobs even reacted to the shots. I am thinking this is a bug with the mobs themselves NOT archery. You also can see the same thing when you try to throw a long range spell and it collides with the terrain behind them but more testing is required.
Logically I have two dogs and I poke each one, dog 1 barks while dog 2 does nothing the difference is the dog not the finger.
I think Meepid has the correct explanation. And probably also explains why the poll is 50/50 (Yes/No).
The tilt fix that the OP posted only affects the angle at which the arrow is shot, the "auto-aim".
The second fix that Azura linked that Meepid is talking about affects the range at which NPCs are given scripts/AI to perform.
People were confused over their results since they were missing shots on NPCs that are
drawn visibly , but don't actually exist in terms of scripting, pathfinding etc.
I guess the way to think of it is as if the NPCs that arrows go through at long distance are the equivalent of "grass" where they can be seen, but don't interact with the player. When you get closer than 4000 game units, the game decides "hey this isn't just grass, this is now an herb!" (or "this isn't just a visible NPC, it is now a visible and interactable NPC")
While NPCs that (for some unknown reason) are allowed to have scripting/AI at distances greater than the 4000 can still be interacted with (hit).
Whether or not the
fVisibleNavmeshMoveDist=12288.0000 fix breaks other parts of the game, I'm not too sure about. But it does fix the distance-shooting problem (even without a tilt fix).