....
they don't give the answer because they don't have any - that's the kind of 'experts' they are.
for me, they are just full of shit - what they do has zero to do with science and 100% to do with their beliefs driven by a subjective perception.
seriously, I am not aware of any hacking tool, or even a serious theoretical paper, that would successfully address a problem of brute forcing original sentences made by a human brain. make an original sentence (one that you can't just google) of ~20 words and I am betting all my bitcoins that no man armed with the fastest computer is going to brute force it before we both die......
That's your subjective perception.
Try this view.
Take 1000 humans, ask each of them to generate some phrase / sentence that will be used for "a password."
Now take the results, the 1000 sentences, and submit them to brute force attacks using English grammar and a million or so common phrases. I wager we break 10 within a couple of weeks.
Give them some time (e.g. one week) to create this password.
That's unacceptable, right?
How about you try this.
Take 1000 humans, ask each of them to generate some phrase / sentence that will be used for "a password."
Tell them that the sentence may be as long as they like, but you have a very powerful computer that will try to guess the password they came out with.
Also tell them that if the computer will not guess their password in 1 year, but they still remember it, then they will be rewarded with $1000000.
Now, good luck with cracking that!

Well, now you are shifting the goal post from your prior argument of "some English sentence with 20 words."
A. That self-selected, human generated phrases within a certain length "might or could be" safe from attack?
B. Or that they "are safe from attack?"
(A) nobody would disagree.
(B) is not defensible without narrowly constricting the domain and the premises.