It’s appalling how lazy people are these days, immediately rushing to social media groups to ask questions when a simple search or reading the manual would have been enough to answer them 95% of the time. So I tend to agree with your observation.
When I mentioned a combined file in my previous post, I was obviously only talking about the Engine OS file downloadable from the website for an update via computer or USB, not the Wi-Fi update.
During the Wi-Fi update, the hardware ID of the device you are using is sent back to the server, so the server only returns the firmware compatible with your device.
A combined Wi-Fi firmware would therefore make no sense.