Given the number of NPCs I think you are talking about, I have a feeling a separate page for each city/town makes sense (for instance [[Civic Diplomacy for Ca'ial Brael]] or some such name).
I would suggest a section for each position (soldier, noble, etc.) with the NPCs listed by level. Each section could just be a single table with listing: level, NPC, location (e.g., crafting area), and what ever other info you have. The NPC name would be a link to the NPC page where, someday soon(TM), we can add the detailed location info and other stuff.
You could add a section to the bottom of the
Civic Diplomacy page that lists the town pages. They can all be in [[Category:Diplomacy Sphere]] for now (or perhaps a specific subcategory???).
Bottom line is, of course, that getting the data in is the big step. Rearranging it and cross referencing it can be handled after people see what is available and what their various needs are.