T,
I think there is a bit of a chicken and egg thing in my mind. The conditions should dictate the organization. This also gets into one of the things we discussed awhile back - what is needed in one location is not the same as another - you might need 2 of one and 0 of another. This is useful in that it conserves resources, but difficult in that is not the way we like to do business - we like cookie cutters. Building botom up refinement requires asking good questions and having people who can understand the answers and articulate them into the right requiests.
I think one of the things we could be doing right now (and probably are) is getting a feel for how far along things are by region/province, ISF component in cities/provinces, and Iraqi government systems so that some forecasting can be done about where we anticipate them needing assistance.
Every area has its own challenges in regards to sustaining forces, but I think what you'll see is the areas with greater security conerns will be the ones with CF units still in a reinforcing role - we won't reduce all at once. Gauging where Iraq is along the road to recovery is tricky - metrics for security and stability are subjective, so applying resources is a bit of an art.
I know its not what you were asking, but that is what came to mind.
Regards, Rob