Managing Heterogeneous Agents — Placing Claude, Codex, and Antigravity by Strength

The conclusion first

The heart of running heterogeneous agents is "place by strength, and draw clear boundaries." Splitting models with different characters across roles raises both throughput and quality more than running many copies of the same model.

Why heterogeneous

Each model is good at a different grain of work. Give everything to one model, and its weakness becomes the whole system's bottleneck. Mixing models lets them cover each other's gaps — as long as it's clear who owns what.

An example placement

Marblo uses this split as a default shape:

• Claude — backend implementation: complex logic and long-context work.
• GPT/Codex — frontend: UI composition and repetitive component work.
• Antigravity — testing: verifying the code that was written.

This split is a starting point, not a fixed rule. Adjust it to the project.

Draw clear boundaries

The most common failure in heterogeneous work is two agents editing the same file at once. Split tasks by file or module so ownership doesn't overlap, and when needed, run them in parallel inside isolated workspaces.

Coordinate from the center

Even if each agent runs well independently, you only stay in control when you can see who is doing what in one place. A central orchestrator assigns tasks, and a kanban board reflects state.

Takeaway

Heterogeneous orchestration isn't "using many models" — it's "putting each model in its right place." Placement, boundaries, central coordination — those three are the backbone of managing it.