When to use multiple agent profiles vs. sub-agents

The rule of thumb is straightforward: if a task requires different skill sets, spin up different profiles — each configured with the right model and tools for that role. If a task only needs one skill set but benefits from parallel execution, use sub-agents — multiple instances of the same profile running simultaneously. For example, building a micro SaaS might need five or six coding sub-agents all doing the same type of work at once. But producing a YouTube video requires a researcher, a scriptwriter, and a graphic designer — three genuinely different skill sets — so you'd use three different profiles, each backed by the best model for that job.