Finding: The 4-model split is near-optimal and should not be changed
Opus 4-6 xhigh (orchestration/reasoning) + Sonnet 4-6 (data collection/delegation) + Gemini 2.5 Flash (simulation volume) + Gemini 3 Pro (entity extraction accuracy) is an excellent division of labor. Each model is assigned to tasks matching its strength profile: Opus for deep reasoning, Sonnet for speed+volume, Flash for cheap parallel agents, Pro for accurate extraction. No configuration change here would improve quality.