i didn't know the basketball team was on the field (the corps was called Magic of Orlando), all kidding aside, they didn't have a cadets corps...they were one corps. that's kinda the point of this thread i do believe...it's not that these corps couldn't compete and be successful as world class corps, but that it is not the purpose of these corps to try to do so.
as far as those that age-out of cadets corps, it may not be that the corps is loosing sight of the mission, it could just be that the member does not quite have the talent to make it in the "A" corps, but does very well where they are. or maybe they have such a good time as a younger member that they choose to stay in the "B" corps (i don't really know how they work so i don't know if a member can choose).