Race Radio said:
The cobbles are only going to matter in the last 2-3 laps, by that time the group will be thinned out
But it is the constant battle for positioning in the previous laps to be at the right place before the cobbles that is going to make the thinning out process much more brutal. This is how it works with cobbles : They themselves are tiring, but the battle to stay upfront before the cobbles is just as taxing.
This is why you often have on cobbled races such as RVV or Paris Roubaix breakaway riders finishing in good place, as opposed to on LBL or Lombardia where the bunch always gets them.
Last year riders like Roelandts in RVV or Gaudin in Paris Roubaix would have lost too much energy constantly fighting for position in the peloton to reach the standing they did by standing back. But because they attacked from afar and could therefore pace themselves before each cobbled sector/hill and not lose all that energy in the positioning battle, they managed to last a lot longer.
This peculiarity of cobbled races : before each sector there is a battle for positioning, and that battle starts at the very firts cobbled sector, even if it is 150kms from the finish line, is what could make this race really hard. More than the difficulty of the cobble themselves. In the case of that short partly cobbled section, the battle to be ahead because of the narrowness of the paved portion will have the same taxing consequences.