Actors with a count of 0

[Rhaskos]

While looking through the Actors in the Creation Kit, I've noticed that quite a few of the actors have a count of '0' in the count field in the object window. I know that some mods might use them, but other than that, does Skyrim even use them? Would the count be 0 if that actor was randomly spawned into the game by some means, or does the count account for that too and those actors aren't used at all in Vanilla Skyrim?