No "may be" about it. There is no benefit to having bad models write your code, and there's no benefit to "plan" mode. Plan mode is an outdated 2025 concept that should be removed from standard harnesses.

There are 2 scenarios for dumb builder agents:

1. Your "planner" actually implements the project almost completely, finds all the gotchas, solves all of the emergent problems, and fully plans the solution.

2. Your "planner" takes a half-assed first attempt, solving none of the major problems that will arise during implementation

In scenario 1 -- just pay cache output on a few more tokens to finish the project. No need to spend twenty minutes pumping a few million tokens through deepseek regardless of how cheap it is to do so.

In scenario 2 -- good luck getting quality output

I do think this "software team" LARPing is an engineering version of AI psychosis. You can get all of the little parts humming along, sending messages, and looking really cool. You can even convince yourself that all of these busy little bees actually make better product.

But a frontier model working alone can produce better output in a tiny fraction of the time. Just build the thing.