Other than the characters personal wealth, he spends points on allies, which are his followers. Allies that are followers provide manpower, independent income and special abilities or insight. I've oversimplified it in the game and clarified it.
So with a lord his primary asset is his revenue generating like a village, manor or city. He may not be directly managing it but he sets the benchmarks, goals and management. He manages the managers, so there is some basic IQ-5 or admin or merchant roll to over see the steward or chamberlain. Those other independent income sources, those he's delegated to his knights, lords, yeomen, etc... Are simplified as allies with 3 basic duties - manpower, duties/taxes/gifts, and their talents/insight/counsel.
I'll illustrate and simplify it in the GURPS low tech lite I'm working on. So a lord has a messy character sheet when it deals with his relations, in fact it is best mind-mapped. A lord will also have retainer experts and yeomen. Secular lords can even have religious retainers as wells as religious leaders have secular lords. This whole mess is great role playing and is actually realistic. But the key mental note is that these allies are black boxed. Maybe I'll make a stat block.
Note that to some historians, the church is the alternative career track for nobles. Most bishops and pontifs are nobles and have families. Some noble clerics try to build their own dynasties within their religious bureaucracy.
Well ill make the doc available should someone tweak this later on to be Han, japanese, Indian, or middle eastern centric, or more suitable for their setting like GoT.