Here's an idea I had: make the Totem for a Tribe be a Bank. The area controlled by the Tribe is controlled by how much stuff is in the bank. The bank could robbed by PvP players. Here's the details:
1) the Totem serves as a storage bin for the Tribe, the Tribe's bank
2) the area controlled by the Tribe is based on the contents of the bank
3) Tribe members place/contribute to the bank, thereby growing the Tribal area
4) enemy players, outlaws, could rob the bank, by coming onto Tribal lands and looting it
5) Tribe members cannot be attacked on their lands, but their bank can be looted
6) if a Tribal member tries to attack the bank robbers, they become PvP enabled, so the bank robbers can fight back
7) Totems and villages cannot be destroyed, but they can be looted.
With nothing in the bank, the Tribe's radius would be very small, like a homestead.
Not a good idea imo, and very hard to implement. So if someone robs the bank then the tribe area shrinks immediately ? What if the players are offline ? What would you fill the bank with ? If only the amount what counts people would fill it with grass. If you want something more valuable that means that the game needs a system which controls how much is an item worth. Thats kinda impossible, if they do it that kills free trading.