Company A recently acquired Company B. A cloud administrator needs to give access to the accounting and time-reporting systems for Company B's employees. Company A's employees use a single account…

Adding Company B's identity management system to the federated identity system establishes a cross-organizational trust relationship, so Company B employees authenticate with their existing credentials and gain access to Company A's systems - this is the core purpose of federation, eliminating the need to duplicate or recreate accounts.

Creating new accounts in each system defeats the purpose of federated identity and introduces unmanageable credential sprawl requiring ongoing manual synchronization.

A shared account eliminates individual accountability, violates the principle of least privilege, and is a security anti-pattern that auditors would flag.

Mirroring accounts in Company A's system creates duplicate identity management overhead and requires ongoing manual updates whenever Company B adds, changes, or removes users.