>- How many individual components do you need for it to emerge?

If it is about the relationship between components, then I would imagine just two. Then it is a matter of scale.

This seems to be anathema to many people. I'm not sure why but the notion of something having a tiny bit of consciousness that is imperceptible seems to be unacceptable. There are so many things that we cannot comprehend at small scales. Nobody really has a handle on how large a Planck length is.

For some reason it comforts people to think there is a threshold at which it all switches on, but for what reason would there be a threshold?