In my opinion the mod mechanics works against lords

[Erk]

We did that in Borderlands v1.

The problem was that we might not have calibrated well the distance to castles and rewards. People did one or two trips top, so you wouldn't see much serfing.

The problem with castles and rewards in this scheme is how to make castles constantly profitable. That means you need a fraction of the players serfing all the time, which simply doesn't happen nowadays.

Limits on banks and rewards need to be adjusted.

Also, I wouldn't neglect bandits. Else it is horribly boring. Our mistake in borderlands was not to allow for many routes to the castle. There was one long way to it, making it impossible to ambush resources without getting immediately counterattacked by the faction. No  possibility to hide elsewhere!

 

[Splintert]

The only version of Borderlands I know of suffered from a permanent merchant faction and a centralized village where everything took place. The castles were far away from anything, discouraging serfing of any kind due to the long travel times.

Either way, if there's one thing I don't neglect on most of my maps its bandits. There's many ways for both factions to capture and for bandits to escape. They will get combat tier classes, whereas commoners do not. Hopefully this creates a blunt-and-obvious identification for the difference between combat neutrals and neutral neutrals. Also, the bandits have 2 areas where they can be considered 'in control', one of which has exports for all resources with tax to a chest that is in their main base. They do not have an armoury nor any way to procure weapons on their own, however, so they may want to avoid making too many enemies.

 

[Erk]

Borderlands v1 had only 3 castles, no neutral factions (then borderlands 2 changed everything). But the problem with people not serfing "often enough" is common to all maps. At any time, you will see more tons more warriors that serfs in any single scene. Exclude brief moment after reset in scenes without bot banking.

This is a major problem for the export to chest idea.

The only thing that comes to my mind is high drop rates (1/3 or above) together with limits on bot bank withdrawal. That way you force people to make money several times per session. Keeping in mind though that money making should be relatively quick. I would rather see many transitions between warrior and serf than the current state.

Distance to castle was a problem in all borderlands. That should be kept in mind.