Arcana smart contracts together with the Arcana Gateway implements the core system logic for providing app user data privacy and access control. Note that a typical smart contract once deployed on the blockchain can never be changed. But Arcana smart contract implementation ensures that it can be upgraded.
The primary aim of having multiple smart contracts for Arcana Auth is not just to implement and choreograph the core system logic of user data access operations. It also ensures that the Arcana Auth protocol, in general, is upgradable.