Overview
The model comparisons in Lesson 1 suggest that the major systems are close in overall intelligence. The benefit of orchestration comes from stacking smaller advantages.
If one model is slightly better at front-end design, another is slightly better at back-end programming, and a third is easier to inspect and steer, a multi-agent system can combine those strengths. A few percentage points may not matter for a simple task, but they can matter when the project is complex or the output is at the frontier of what the models can do.
There are also context benefits. A front-end agent does not need every token of the back-end discussion. A testing agent can inspect the output without inheriting every implementation assumption. The orchestrator maintains the project-level view while the workers operate in smaller contexts.
This is why multi-agent systems can improve more than speed. They can also improve the quality and independence of reasoning.