Yes, and I'm arguing that the post is over-simplifying. As I mention, for small plans, it's probably easier to have the big model just do it. But for large, multi-session plans, it's cheaper to let smaller models execute the bulk of the work.

Perhaps, there's a small change that might work better here - if we use a different agent (by creating custom agents) for plan and implementation, then the switch to the implementation agent wouldn't end up re-reading a lot as the new agent would have fresh empty context. I implemented this[1] from one of the posters on HN and I think it'd work well with this problem too. Would be great if you could point out if my understanding is wrong.

[1]: https://www.stavros.io/posts/how-i-write-software-with-llms/