This is actually the author taking two extremely abstract scenarios from playing ‘Victoria 3’ and the ‘English Peace’ MOD for ‘Hearts of Iron 4’ and stitching them together…

To make Greater Germany (Großdeutschland) and Spain share a border, the author directly used ‘divine power’ to squeeze up a piece of land from the Mediterranean.

As for the areas outside the visible map: over 90% of North America, Central Africa, and South Africa are colonies of Otherworld Great Britain, which is the foundation of Great Britain’s confidence to ‘single-handedly suppress’ the European continent.

This is the link to the map. you can check it out!

https://files.catbox.moe/b2wksp.jpg

***

Thanks to user caleredhair for the tip!