I would suggest a system like in wurm online where you can buy land as a tribe or a homestead.
This is how it goes you can build any where with out buying land and your buildings and all have a rate of decay. walls and all can be repaired and improved the better the quality the longer it takes for them to decay slows rate down but they still decay.
If you buy land your walls and buildings dont decay as long as it's on your property you bought. Tools decay with use so do other things just buildings walls wells and stationary things dont decay.
If you quit the game and no longer have a active account all your stuff starts to decay faster to point it rots away freeing up space for new comers who plan on staying.
This type of system would help homesteaders be able to have larger land masses which will help problems im seeing we are going to have in the future when farming and all come into play. First how many sqaures will it take per field? How many different crops is there going to be? Will there ever been animal breeding if so how many sqaures will that take? Will they need fence to keep them stationary and not run back off in the wild? How big will the fence need to be? All this is going to cause problems with out a way to expand land.Specially for home steaders.
What will tribes do with 50 people in them will they have room for tribal crops and breeding grounds along with there players housing?
Some way to purchase more land should be an option. and have benfits for doing so like no decay on stationary obejects that never move. Wurm online has this pegged real well. I would suggest this or something very similar to it to help these issues ive listted for the exspanding world of Xsyon.
Inh wurm you can buy money online use it to buy land deeds and then determin the size you want 10 by 20 or 50 by 50 lot. Of course this feature has a upkeep prise every month which i think is fair.
Food for thought.
How would you deal with land space for farming and breeding and all as Xsyon exspands?