I agree, a better way to specify order would be helpful.
I think the ultimate way might be to have "sets" that you can add multiples of, for each column. A set would basically be what we have right now. So, each time you add a set, it can be a regex or a checkbox list of things, and you can specify ascending or descending. Then, you can add multiple sets to a column and have different sets for different columns.
This way you can have a group of things that go at the top and a group of things that go at the bottom, and specify what is on each column. What are your thoughts?