Maybe he doesn’t agree with it because mark says shit

Probably not, because he doesn't know what Mark says, because he hasn't read the book.

like “pretend your arms are ropes holding the barbell when you power clean”

Can you clearly/lucidly explain why this is wrong?

I guess they’re not authoritative either?

If they just do it because their coaches told them to, and those coaches' coaches told them, ad infinitum, then yes, they're not authoritative.

Just because it's Russia, and Russia is a weightlifting powerhouse, doesn't mean that Russia teaches optimal technique and that we should blindly do what Russia does. That is a logical fallacy.

Russia could teach their athletes to make fart noises with their mouth on the way up from the bottom of a squat. And Russia would still be a weightlifting powerhouse if they did this, even if their athletes were doing stupid shit while they were squatting.