Anthropic says some enterprise deployments improved quality, cost and latency by folding routing and planning subagents into a main loop that loads skills and tools on demand. One customer observed roughly twice the execution speed, but this is not a guarantee across workloads. A migration kit helps teams consolidate one subagent at a time and verify the result with end-to-end evaluations. Subagents remain useful for independent parallel tasks, verification, permission separation and measurable context overload. The recommendation is to define evidence-based boundaries rather than reproduce an organization’s chart in its agent architecture.