Hi,
I would like to suggest you to use our
content staging module instead of the linked document.
Using content staging module the content will be replicated to satellite sites and the content can be changed on satellite site as well (will not be changed on the original site) if needed.
In case of linked document there are two records created in the CMS_Tree table, but both records point to one record in the CMS_Document table (the content of document is stored only once). Therefore you cannot create two documents from one if you unlink the document to make the linked document editable as the common page.
Best regards,
Ivana Tomanickova