One of many military essays justifying the increased military defense against Kyōti, A Tactical Analysis of Kyōti Politics details the difficulties in invading Kyōti with the symbiotic relationships between the clans. Its primary message it that a single clan is weak and overspecialized, but the relationships between the clans give them strength.
The essay was written by an organization called Jastor who tried to bring a clear-headed view of military matters without letting the individual researchers be influenced by political pressure.
Quotes
Over the centuries, the clans have specialized not only in their powers but what services they offer the world.