List development. Drafting wise, to be honest I wouldn't classify anyone as being a defender or a midfielder or anything else (outside of clear KPPs). The role should be more dictated by what they have the capacity to do, not what position they have played between 14 and 18.I think I'm a little confused. Is your post about drafting or development? Do you mean the idea of drafting flankers from u18s and expecting them to be AFL midfielders won't work?
If there was a utility 'defender' on the list that had good speed and endurance, I wouldn't train him for the backline. Sure, go ahead and play him there, but primarily I would be training the players with the capacity to play midfield, as midfielders.
Perhaps we already do that, but I don't know - but I do think that atley is a recent example of how backline to midfield struggles.
I think the whole 'back 6' is a concept that doesn't make sense these days.