Model selection is becoming org design. Marcus Moretti, an engineer at Every, describes @AnthropicAI’s lineup this way: “Fable is the CEO, Opus 5 is a senior engineer, Sonnet 5 is a junior engineer or analyst.” The models are designed to work together in one system. Some orchestrate, some write, and some debug. Specialization lowers costs by routing routine work to cheaper models. You wouldn't have a CEO reformat a spreadsheet, and you wouldn't ask Fable to rename a batch of files. Read the…