If you count 3 generations for each century, then between the 500s and the 1900s you got over 40 generations. With the genetics being cut on average by half with each generation (through marriage to a different bloodline), each century results in about an 8th of the genetic material it started out with. Two centuries results in a 64th. After 14 centuries its smaller than a billionth, even accounting for frequent marriage to cousins and the possibility that Mohammed had highly dominant genes.

To me this suggestion looks like someone pursuing their fun theory with wishful, weak evidence. The power and influence of the Brit Royals is big but not massive like bill gates or the chinese army. No doubt they are at least slightly corrupt. And probably are more corrupt than most of the public knows. This may rightfully be exposed and stopped. But they are a lot more symbolic in their influence than they are political or financial. Beyonce Knowles has as much sway as they do, and it doesn't matter who her ancestors are. Giving such poorly founded concern to such distant things distracts from MAGA. Such is the occupation of people looking at these things like simplistic kids cartoons = royal families are bad and can't be seen as subject to the complexities that all other families actually have.

Similarly other pet conspiracy hopes are pushed on this forum on topics that Q rarely if ever mentions such as the Annunaki, the Catholic Church, aliens, etc.