When you rename files that are combined, you can select a region. For my scope of work sometimes the Design files are different sizes. When you select a region, all the sheets must be the same size for it to work. I have found work a around, if you name the bookmark instead of the tile. The files that do not name correctly stand out. You can then narrow it down, but its time consuming. I suggest at the "Create Labels" Page Region you add a media size. Arch D, Arch E, Custom etc..If the Tile or Bookmark does not name, name it by the media size and page number. (e.g., Arch_D_Page_3, Arch_E_Page_15).