Everything in the human body is a collection of cells.
"But the body isn't homogeneous! It's just mostly homogenous" is a splitting hair argument even if I'd believed you'd kept the plot.
The fact that you even acknowledge it is splitting hairs indicates that you are aware that your analogy is flawed as you can't really think of the body as just cells and that is in direct contrast to systems we discuss in which everything, not mostly, are a certain way. Your body is not mostly cells in the strictest of senses. It is lot of non living material that is a mix or organically made structures as well as various gases, liquids and solids.
But yeah, the analogy isn't perfect. And the academic nature of the metaphor's subject was obviously going to invite some rube to point out how it's not 100% spot on and how that's well worth talking about.
You're just arguing my greater point anyway: Your chosen level of perspective with these metaphors (and real issues) will invert the design philosophy. At one level, everything is different and using different means for the same goal, at another level, everything is the same and using the same means for different goals. If it's not organs, then its cells, then its "extracellular material and are dead cells different from live cells!?", then its atoms and then quarks.
But please, go ahead and educate me on how atoms aren't all the same and how that too is a critical point to be made in this conversation.
The second, which speaks directly to the concepts talked about, is the idea that "everything in the body is a cell" is a poor analogy to use to try to articulate your idea either supporting or not supporting the original posts concept, and you got salty when called out on it rather than have people simply agree with your "amazing insight".
PS I love this game.
More importantly, the perceived conceptual integrity of the human body is rather philosophical was put to question by Roger Penrose in his JRE episode where he talks about why the distribution of motor functions makes no sense ("the foot and walking are over here", "running is all the way over there", to paraphrase) all and we likely need a new physics model to explain consciousness as it arises in the physical brain.
Biology moved on from such an Aristotelian perspective for good reason, to slightly alter something Spinoza once said, we don't know what a cell can do. Our physical being is a radical aggregate that we don't even fully understand yet.