IMO not sure what good adding a “tag” is, because it has no real meaning, other than saying “look at me, there’s another file open with the same name but in a different path”. Maybe some other non-numbered means could be employed on the tab to notify the user of this situation? An asterisk on the tab maybe (although maybe not because convention with that in other programs might be a changed-but-not-saved file…)

So in your example the (1) and (2) are really meaningless tags. They become meaningful to you, I guess, after you work back and forth between them a few times, editing text in each one–in your mind you will associate 1 with the Juice file and 2 with San Andreas.

The following doesn’t extend to more than 2 files with the same name, but why not open one of your files in the secondary view (right-click tab, choose Move to Other View)? Thus you will have one in the primary, one in the secondary, where it is probably just as easy to remember which one is in view 1 and which is in view 2…as it would be to see those numbers on the tabs.