With the great big update incoming, I think with the overhaul of the way factions work, the Leger is, right now, insufficient. Specifically, I think it needs to display enemy factions as well as noble houses and settlements. If this is done of course, it would be best to do something along the lines of separating factions of the same types into expandable/collapsible folders in order to avoid clutter.
On that note, if some statistics were also added to the ledger, it could come to contain a wealth of information to help the player: known camps/ruins/city-states of a given faction, general faction size and strength and maybe even a randomly generated background or personality tidbit to make them more memorable than just “the bandit network occupying those hills there.”
Edit: On that note, the death of an entire faction should get some recognition. Maybe an event pop up? If the player did it, especially if they did it more or less single-handedly, maybe even a reward? Maybe wiping out a faction could be an ambition?