Niamh Fisher-Black was there for a while, and she did try to disrupt cohesion in the valley, but as soon as Alpe d'Huez started, she exploded and had to just suffer her own way in.It's complicated though because so many other riders were in a position to move up significantly in GC, Kasia was always going to find a group to help keep her in contact, Brands effort was all about getting into the top 10 which helped Kasia massively.
If SDWorx were functional as a "team" they'd have left a rider in that group spoiling turns to defend the breakaway.