An opus is longer than a sonnet, which is longer than a haiku. Hence Opus > Sonnet > Haiku.

> Suggestion for a better naming system: use the words "Pro", "Plus", etc.: Claude 5 Pro, Claude 5 Standard, Claude 5 Fast, Claude 5 Mini.

This is not possible: Standard (Free) / Pro / Max are plan names. Fast is a mode.

How long is a fable though?