While looking at some of the scanned LEGO catalogues on BrickSet, I have noticed that the UK catalogues (at least the ones I looked into) seem to be ordered "backwards" compared to what I'm used to from Germany: They start with LEGO System (or even Technic) pages, while Duplo is appended at the end (e.g. look at the 1997 one).
In German catalogues, in contrast, pages are invariably ordered roughly by age ranges, i.e. the catalogues start with Duplo, followed by Basic (or whatever it was called in the respective time), followed by "System" (town, knights, space, ...; possibly starting with juniorized town in the years that was a thing), followed by Technic.
Is there a specific reason for that? (e.g. is that the usual way to order toy catalogues in the UK vs. Germany, was it just started differently and then LEGO stuck with its respective tradition in the respective countries, etc.?)