This is not a contradiction, as the word "but" suggests, as I was writing about 5...a6 6.Be3 g6 and now I do not think 7.Be2 suboptimal. Do you?

Why should playing a sound setup in which Black has committed himself to a suboptimal defence be less challenging? Sounds too much like a positive version of LDZ's eternal "coward" argument. I know you don't mean it that way, but I still hope you get the point.
Try another point of view. If Black was obliged to play ...a6 in the Classical Dragon (new stupid FIDE rule), don't you think the Classical would be much more popular?
The bottom line is: do you want to play that as Black or not? And that question you have to answer for yourself.

Of course White does not need to play f3 in that case: 5...a6 6.Be3 g6 7.Be2 or 7.h3 Bg7 8.Bc4 and White argues that ...a6 is suboptimal. That does not mean that these lines are bad for Black.

Indeed, that was also my idea, also not going to play it against Be3, to avoid yuguslav.

Hello there, recently I bought a new book about the najdorf (The sharpest siclian, which I like A LOT). But I'm thinking about playing some lines with 6...g7-g6. (I think it is called the Dragadorf but I'm not sure). Especially against:
6.a4 g6
6.Be2 g6
6.g3 g6
and Perhaps even against 6.Bc4 and 6.f4
I play 6...e5 against the English attack.
Are there some move-orders which might prove difficult?