When to Use One Model and When to Use a Team of Agents

On a recent AI capacity buildout, I scheduled a control plane node into an early cutover wave because the 2 week traffic snapshot I had of it looked effectively isolated. It was not. It was a monthly capacity reconciliation job. On the 21st it woke up, half the reconciliation now crossed a data center boundary, and pipeline latency moved from roughly 10 minutes to close to 60. The graph was not wrong. My observation window was. We had used a 2 week capture window as the source of truth for a job that only ran once a month. The failure mode I care about is a reasoning model that looks right on the evidence it was shown, and quietly wrong on the evidence it was not. A single model handed all of this evidence will smooth the contradictions between it and produce a confident answer. A small team of specialist agents, with a coordinator that names contradictions instead of…