It may seem a little contradictory, but the part on bikes settings is definitely factual.
https://www.mxlarge.com/news/dirk-gruebel-interview
Dirk Gruebel: What I don’t like, is they say we changed their track, this was no tour Redbud track, but that is BS. It doesn’t matter if you change 30% of the track. The most honest guy was Roger. He said he could turn his back and tell when the American riders go past, because they rev their bike like shit and the bike goes nowhere. Prado on a 250 stayed in front of all those 450s, because he was shifting and riding in the correct way. It is lame and they blame the supercross, but I can tell you, their bike set-ups were wrong in Lommel, and they were wrong in Latvia, and they were wrong in Redbud. I saw it with Dungey who was in our tent, and you try and help them out, but they stick to the supercross settings. The front is too high and the back is too rigid and they can’t make the turns on a normal motocross and that is where it all starts.