2-level tree:
sol high/xhigh as the parent (orchestration, integration, etc.)
luna max fast as the leaves (impl, scouting, work, etc.)
astra high/xhigh in a dotted line to the parent (sol asks it for the initial plan, then continuously resumes at checkpoints to review outputs, and recalibrate the plan forward)
fresh ephemeral astra xhigh when something needs a fresh perspective