Hierarchical Architecture and Its Failure Mode

Hierarchical is supervisor nested. Manager agents over sub-managers over workers. CrewAI `Process.hierarchical` is the textbook version: a `manager_llm` dynamically delegates tasks and validates outputs. The LangGraph equivalent is `create_supervisor(create_supervisor(...))`. It is the natural pattern when the task is a real org chart. It is also the pattern most likely to collapse into managerial looping — manager agents assign work poorly, misinterpret sub-outputs, or fail to reach consensus. Sequential often beats it.