How often is this updated?

I actually assist Emery in maintaining this sheet along with one other UrbanMyth. I don't actively go searching if people have changed their allegiances or names or added duchies or so on so if someone contacts me and I can verify who they are I update the sheet.

Kingdoms, of course, are rather static. Duchies are less sure but also static for the most part so I can pretty confident the NA-W tab is correct as to the current community.

That being said if there's backdoor dealings going on or things people are keeping private to their communities for their own reasons the sheet won't reflect it :)