How is the precedence / priority order of Luminis layouts established?
From SCT Luminis System Administration Guide, Version B, 7/7/03: The precedence sets the priority of the layout fragment relative to other layout fragments in the system. The higher the number, the greater claim the layout has on the left-most tab position in the user interface. If two layout fragments have the same precedence, they will appear in the layout in order of appearance in the dlm.xml file.