Certain policies (like those favored by the Kitabatake or Northern clans) unlock hidden stat boosts.
Placing "Linked" officers in the Council allows for faster construction of high-tier facilities. How to Activate the Link nobunagas ambition awakening power up kittenoke link
Linking specific "Kitten" (Northern Trade) hubs increases gold income exponentially. Certain policies (like those favored by the Kitabatake