On the one hand, guild halls are super cool. On the other hand, it's a lot of content to cover. So, yes, but you shouldn't feel like you need one to be relevant, and they don't have to be as big and wondrous as the Tomb of Nazarick. In fact, maybe better that they aren't so massive and labyrinthine... Nothing says you couldn't create or capture new holdings, of course. EDIT: Added a short FAQ section to the top, since I know others will be wondering about that. Thanks for asking.