There is a euphonium player who auditioned and made the US Army Field Band in DC last Fall. He marched JSU, probably could have marched anywhere if he wanted. He chose JSU.
This proposal is ridiculous and not a good one, as there are already talented musicians choosing to march the "lower tier" corps.
However, It would improve the top corps with the whole dealing with drum corps rookies, and not having to teach them about 'what goes on' and 'how to go about things in drum corps' and having the rookie season under your belt.
But, with the bond you grow with your corps, what if these rookie marchers decided not to march anywhere else, and just stay put... That means, no new marchers for the top 6 corps, AND possibility of not having enough people to fill the 135 limit, AND ultimately the top 6 corps fold because of lack of membership. HAHAHAH!!! YEAH RIGHT!!!
It's really not a good idea whatever way you look at it.