Why not just one agent that spawns sub-agents?
One agent means one harness, and one harness locks you into one set of models, tools, connections, and skills. Each agent here runs its own stack: its own model, its own MCP servers, its own tools, connections, and loops. Thorp speaks to a bank and a chain. Ada speaks to a search index and a private corpus. Push both through a single runtime and you have to pick the model and tool set that serves neither of them well. The industry is standardizing some of this, but a single agent can still only do what its one harness holds. Six specialized agents raise that ceiling.