I'm having another problem, I've wiped out the Westland faction, they were at war with multiple factions, but I captured most of their lands. Anyway, I desperately need Lords, I only have Brienne and 2 good-guy Lannister men. Joffrey's in my prison, said on the notes he joined my faction, no way he's going to rot LOL. My other companions are too low level for now. 100 days after the faction elimination the Westland lords are hiding out with 4 or 5 troops, they won't join any other faction. I see in the patch notes " Fixed an issue where some Lords would stay as part of an eliminated faction." I'd sure like to snag a couple of them, I talk to them with a high persuasion skill, and 100 relations with many of them, but they still want to stay with their wiped out faction and stupidly try to raid my towns with their 5 men. If there's no way to get lords from defeated factions, or any other, it is hopeless to try to start your own kingdom, companions aren't enough and it takes them a very long time to get any efficiency at all, with the exception of Brienne.
Edit: Another 150 days in game, no change for the defeated faction lords, however the problem I thought I had with snagging lords is resolved. Dorne is getting smashed by the Reach, down to 1 town, and I was able to convince 5 of their very upstanding lords to my cause.
Couple other things I've noticed, not a criticism, but just to aid you in being aware of them,.
1. There is no access to the prison in Arbor that I could see, so rescuing captured lords problematic.
2. Casterly Rock has some path-finding problems for assaulting troops. A short stone stairway in particular is used by defenders coming down to fight your troops can't be used by your assault force. They can slaughter your troops with ranged weapons without your infantry being able to retaliate, they just run in place.