I guess according to this thread the ability to sort the Levels of Detail has been on the wish list for at least a couple of years. Maybe by posting an idea here this can put a little more credance to it.
http://forums.autodesk.com/t5/Autodesk-Inventor/Sorting-arranging-level-of-detail/td-p/3103308
Please add the ability to sort the LOD's in what ever order makes sense to the user.