What about something like this.
Villages build up power level over time (mechanic is already active), once the village hits 100% you can start making buildings that are realm related. Grotesques and Menhirs give a very small bonus to the area near they are built. Once your little village is bursting at the seems with menhirs and grotesques you can start to project your power as a ruler of the area. Now a coronation stone can be built that amplifies your bonuses and you can challenge Thingwalls similar to how you can now. This level of progression also grants the state burial and from the coffers. Conquering the thingwall you are built in is similar to what a realm is now and it amplifies the buffs to their current state. Now that you actually have a zone of control you can begin adding Thingwalls.
This way there is a path for the lowly motherfucker to get some buffs and somewhat control their fate while the faction bois still do their own thing and stuff.
Mats would continue to be valuable through out the world as there would be a greater demand for them and an actual reason to continue to make and use them.
Or like make it so even if I'm not in a realm I can expand it and get myself the fucking buffs. So simple.