Sembian and Zhent Guilds
Churches of Lathander, Oghma, Tyr, Tempus, Bane, Chauntea, Mystra
Elminster, Colderan, Rhauntides… the odd Red Wizard
Mercenary Bands and fledgeling dales
You could definitely model this with Birthright. A number of clear adventures could ensure … recover the pendant of...