Having high relation in Warband meant you had an ally who would might leave their faction to join you and would agree to help you with big fights and would be loyal to your cause. I don't know what it means in Bannerlord? Just cheaper influence costs? It's a weak and one-dimensional mechanic.
YES! One of the only reasons I kept playing was because Diplomacy Fixes messenger system made life so much easier in this way. I'd have given up on the game entirely if convincing a clan to join me meant that I had to chase each clan leader down individually when they're not in an army and pay millions etc etc etc
Having the clans send messengers to you would be so much better. Especially if - for instance - you're besieging their fief and they want to offer you money to go away OR offer to join your faction so they keep the fief.
Having messengers appearing or sending them, would be a good way to decrease the frustration of recruiting clans. I thought a messenger system would be discussed internally?
making companions into clans is a welcome change.
It would be good if there would be a minister or spymaster you could interact with who can find out which nobles are disgruntled and have a high change of recruiting. Don't use the almighty encyclopedia, or use the minister/spymaster to slowly fill the encyclopedia after missions.
I think character traits should be taken into account. A cautious noble would not want to change factions, but an opportunistic one who sees that you are winning might be easier to convince. A lower tier clan might also look at your faction as a way to rise quicker compared to their current faction.
It should be an option to recruit a clan with their holdings when you are at peace with their parent faction. This will of course start a war, but lower the recruitment cost.
it makes sense that a clan with a few holdings wont want to give them up to join an upstart kingdom, But if they can take their holdings with them they might be considering this if they have low relations with their current ruler.
The balancing of relationship with your underlings when giving out fiefs was an interesting aspect of ruling a kingdom. This of course needs other ways of improving relationship when it gets low.
Finally I agree with people that making money the gateway for recruiting is not the best. I don't like the fact that de calculation takes into account your total wealth and uses a percentage of that.
The calculation should solely be based on the needs of the clan that you want to recruit.
Relationship with the clan, marriage, the clans relationship with their current faction leader, renown, similar character traits, faction strength and location of holdings relative to your borders should be the primary considerations for the AI.
I agree that abstracting systems to money and influence hinders the "soul" of the game.