I pointed to Richard Jones arguing that you should only expect scale separation in designed systems. This seems a poor inference to me. Natural systems very often have 'designed' seeming features, due to selection, and he doesn't explain why scale separation would only come from a real designer, rather than selection. Further, it seems natural systems often actually have scale separation - i.e. you can model the system fine by only looking at items at a certain scale, ignoring their details. e.g. you can model planetary motion well without knowing the details of what is on or in the planets. You can model water well without knowing where its molecules are. You can model transfer of heat just fine without looking at where each molecule is.