The Prince and Princess of Orange ca. 1711 being the most recent common ancestors of current reigning monarchs does not preclude those monarchs from having other ancestors. I take overlap into account, using real genealogical data.
Complete overlap just doesn't happen. I use Daniel de Rauglaudre's database for my model, which has the first 15 generations HM Margrethe II's unique ancestors (counting repeat ancestors only once) grow like this:
113 (Johan Willem Friso and Marie appear twice in this generation),
177 (twice again)
270 (twice again, being Margrethe's ancestors 6 times total)
Those 899 ancestors are a far cry from the 32,768 ancestors she would have in the 15th generation if they were all unique people! For comparison her cousin reigning in the UK has 1,317 in the same generation and the Duke of Edinburgh has 895. Why so different? The Queen Mother had many commoner English, Scottish, and Anglo-Irish ancestors, bringing her daughter's total up.
But even two people who are both *very royal* have ancestors whom we suspect do not overlap. The Duke of Edinburgh is descended from Maria Salomea Schweppenhäuser, Gräfin Hauke (1751-1833) while the Queen of Denmark is not. She was of Jewish ancestry and adds many ancestors to the former's ancestry that the latter does not have. Similarly, the Queen of Denmark is descended from Désirée Clary (1777-1860), the French wife of Karl XIV Bernadotte while the Duke of Edinburgh is not. Her ancestors were upper-class Marseillais, but certainly not royal.
It is this kind of growth that is modeled for Margrethe in my video, based on the real data.
Going back to those 15 generations, even royalty have unknown ancestors. I take these into account by assuming unknowns' ancestry grows at the same rate as known ancestors' ancestry. She has 899 ancestors in her 15th generation, including Johan IV of Nassau-Dillenburg (JWF's ancestor), who is Margrethe's ancestor through 197 lines in that generation (2,227 separate lines in total!). But she also has unknowns in that generation, and if I apply a coefficient of ancestor growth consistent with French minor nobility, for instance, it adds another 700 ancestors.
So then by the 20th generation, we wind up with an estimated ~6,000 ancestors for Margrethe, again, some of whom are her ancestors *thousands of times over* and who are the primary contributors to her being royal, but some of whom are unique commoners that she doesn't share with other monarchs. If it keeps growing at that same slow rate in the 20th through 150th generation, as her royal and noble ancestors fade into the Germanic and Celtic tribes of Old Europe, unknown Romans and others, her ancestors, too, start to go into the millions.
Ancestors of Margrethe II von Schleswig-Holstein-Sonderburg-Glücksburg
The Ethnic ancestry of Prince William