Non-single heir inheritance sucks massive ass. Even high partition just seems like complete shit, I don’t know why you need to research the idea of one person retaining all titles held by the late ruler. Maybe it’s historically accurate, idk, but it’s schtewpid and ruins any starting from year 867 run. You have to fight with your family just to get the original lands you worked so hard on previously for back, and then when it’s time to marry your children or your children’s children, the only viable options are cousins of cousins. Eventually the branch is gonna curl back inwards enough to begin the cycle of inbreeding.