Start with the ownership question
If your team already has a clear roadmap, delivery leadership and established rituals, adding individual engineers is a direct way to cover a skill or capacity gap. Write down who sets priorities and accepts work before you start searching.
Look for connected gaps
A dedicated team earns its place when several roles need to work closely together — say a platform effort needing cloud, backend and SRE skills at once. Brief the team around a shared outcome and define how its decisions connect to the rest of your organisation.
Make the operating model explicit
Agree working-hour overlap, escalation paths, review frequency and documentation expectations up front. A title on a proposal is no substitute for a conversation about who decides what. Revisit the model as the roadmap changes.