It cuts token usage because they are using a different service with a different token budget for the reader/code writer tasks.

You can also just delegate this to subagents with Claude Code (though you have a more limited choice of models unless you swap the cheaper models via OpenRouter).

I'm OK using a dumb model as a smart grep, but the whole point of using the frontier models is using their intelligence for the hard stuff like coding.

You can also use hooks to force the use of subagents for this. The stack here is entirely unnecessary