Also, at risk of being excessive, Ferris’ definition of fluency makes his promise for the post doable:
“How to be fluent in a few months” is not that crazy when you’re just trying to be comfortable enough to describe things in a new language.
Plus, what they talk about is pretty in sync with Khatz. Major Khatz difference is fanatacism, and he also talks about being working level proficient in a year (reading, writing, speaking) which is truly nuts.