Would it be an odd thing to say, "She's a methodical, but unorganized person." or "She's an organized, but not methodical person."?
I can't quite have a clear image as to what type of person each adjective [methodical and organized] is used for.
Methodical = following a method. However, the method itself may be disorganised (NB).
For example, when tidying a room, you might have a method of picking up an item at random and putting it in its proper place; you then pick up the nearest item and move that to its proper place, and then the next nearest item, and so forth. This looks completely disorganised, and because you start with a random item and then choose other near items at random, it is indeed disorganised. It is, however, very methodical and may result in a tidy room with little wasted energy.