The OpenAI employee above says that some smaller models of the same generation are better at certain tasks than larger models, regardless of cost difference.

They should have a guide saying "Terra is best at technical documentation and communication, Astra is best at large software projects and research, Sol is good for development" or something like that.

Then he qualified to say it depends on the unique details of the documentation. I don't think its possible. You have to try all models with effort and compare all or go on reputation or vibes.