I keep finding these things as decoy precious items, and sometimes they're oddly connected to other things in a way that I'm not sure I understand.

For example, there's one in Limgrave randomly lying in the middle of a field a short distance away from Boc, and when you approach it Boc's voice calling you over is triggered.

There's also one in Stormveil castle that is strangely pointed out by a corpse in the wall below. The body is lying in a hole in the outer wall near where you fight the knight in the locked room. The body drops St Trina's arrows, which grabs your attention, and then you notice that it's arm is stiff and pointing straight up in a gesture. If you follow where it's pointing, you find an arteria leaf on the rampart up above.

Just now I entered the Lakeside Crystal Cave, where you find Latenna, and as soon as you enter by the site of grace there is a chest that contains an Arteria Leaf. The game directs the player here via Gideon, and then you find this leaf in a chest unavoidably as if it is important.

Am I missing something about what these are used for, or reading too much into this?