What is the point in federating a wiki this way? The point of an encyclopedia is to have structured and consistent information about everything in one place. This seems to propose a model where rules, formatting, notability/verifiability criteria, quality etc can only be consistent within a single server. Information is spread over multiple servers, creating a rife potential for duplicate articles, difficulties with search, and fracturing of the community (I can easily imagine a dozen articles about every even slightly politically contentious subject).

In other words, to me the point of federation is to allow multiple sets of rules (e.g. moderation rules) to exist within a single space, which seems to be contrary to the basic idea of an encyclopedia.