One thought that comes to mind is that the monarch has not only to appoint a credible successor, but also discredit any other potential successors. Check the story of the son of Peter the Great, who was effectively killed by his father to prevent potential succession conflicts in the future: https://en.wikipedia.org/wiki/Alexei_Petrovich,_Tsarevich_of_Russia
Another related topic is preferential cross-cousin marriage which is well known from anthropology. I’ve written about it here, albeit in a bit different context: http://250bpm.com/blog:92
One thought that comes to mind is that the monarch has not only to appoint a credible successor, but also discredit any other potential successors. Check the story of the son of Peter the Great, who was effectively killed by his father to prevent potential succession conflicts in the future: https://en.wikipedia.org/wiki/Alexei_Petrovich,_Tsarevich_of_Russia
Another related topic is preferential cross-cousin marriage which is well known from anthropology. I’ve written about it here, albeit in a bit different context: http://250bpm.com/blog:92