In my setup there are two planes — manager and worker. On the manager plane, all primary agents form a mesh with p2p communication. Each designer connects to 1 or more workers in a star topology, since workers may have questions or get blocked while executing a plan.
The limitation of the built-in agent tool is it doesn't allow nested subagent spawning. But it's normal for a designer or researcher to need subagents — when a plan is done, I use a plan-review-leader agent to review it. If you try mother → planner → plan-review-leader → plan-vs-reality-validator, the nesting gets deep fast and blocks your manager from doing other work.
I wrote a blog post about this yesterday: https://dev.to/neil_agentic/ttal-more-than-a-harness-enginee...
