A judge's job is to pick out the dogs with the best conformation,,condition, and movement, maybe add in temperament, if two dogs are very close in appearance. A judge is not there to assess working ability ,because he can't.
All a judge can do is choose those dogs that look as though they have the best of the qualities mentioned,thereby enabling them to do the job they were bred for.
Scarks /marks should not be a factor,a dog covered with scars might be a clumsy sod ,who cuts himself on a blade of grass,scars are not medals.