If you find that you have two diagrams that can be combined into one you may need to Re Assign the child page Links. This form makes that possible. Normally this is not required though because Page Importing general prevents duplicate.
For example if you append a model that contains a second set of drivers that were not the same as your original ones then you may get duplicated. You can then use this to make the imported symbols use the original driver pages before then deleting the surplus pages.
Click Twice on the Pages that are linked to list first on the diagram that you want to keep then the other one and then ReAssign.