Consciousness is an actual thing. It's not an idea. The idea that somehow a collection of stone objects springs forth a consciousness when arranged in one pattern versus another... is certainly an odd concept.
Temperature for example isn’t a substance. I am not saying consciousness couldn’t be a thing, but it just seems to be an assumption without justification.
As to arrangements of stuff being important, arrangement of individual pieces can make the difference between a watch and a pile of pieces or a person and a dead body. Many emergent properties depend on the specific arrangements of components.
If consciousness were simply the property of a system, then I'd assume it is effectively an illusion. I'm not sure, and I'm not saying this it would be de facto wrong, I'm just saying it's absurd for me to conceive of it this way, because if it is the case that it's a byproduct of a system, then there is effectively no self. It may be the case that that is true, bit it's useless to conceive of it.
When you see an object in reality, you're really making a series of assumptions. What you see is reflected light, and you construct a highly innacurate but useful model of what that light logically implies. Something that is external can only be perceived epistemically, as a sufficiently good guess. There's no evidence we're not in a simulation, so it's a toss-up as to whether anything physical exists at all.
Contrast the concept of self awareness. 'I think, therefore I am' is not a guess. It is a certainty, regardless of the broader context, that somewhere, something is a host to my experiences and thoughts.
Tangent: You can extend that a little bit by reasoning that you exist, therefore the things you interact with must exist as something. That doesn't get you past the possibility of the matrix, but it does escape total nihilism.