How to combine two menu's in Drupal
Instead you can try this Advanced Menu module, Menus can now be merged into other menus. This allows users with the appropriate permission to add links to other menus which are then displayed as if there were a single menu.


  Example:
  
  Create new role "News Manager"
  
  Create new user "News Editor"
  
  Create new menu "News Releases", Set "News Manager" as an editor for
  the menu.