Even if you are a tuba player (which I was too), both activities are judged somewhat the same.
If you look at repcaps, you have "vocabulary" and "excellence" for movement, equipment and ensemble which Onyx receive 3rd, 4th and even 5th place scores. pretty much showing the weaknesses Scott is talking about, and the GE scores show "repertoire" and "performance" had 1st and 2nd place scores, which includes difficulty/demand and how well they perform it. So they were rewarded for demand.
It's something true for DC as well: GE wins shows. Get the GE scores down, and a group can get away with a lot of weaknesses in specific categories.