How can I manage my files in Finder?

I currently own a MacBook Pro (13-inch, 2016, Two Thunderbolt 3 ports) running on macOS High Sierra v10.13.5.

I have a set of Pages documents that I added into one of my tags. They were previously being held in a folder I created. This folder was placed on my Sidebar in Finder. When I highlighted all the Pages in the Sidebar folder I secondary clicked on them and hit my tag of choice. At this point I have a set of the Pages documents in my Sidebar folder AND the above tag.

I proceeded to move all the Sidebar folder documents into the Trash only to see that the Pages in the tag have done the same thing. It seems to me that even though the Pages are in two different locations, they are still being considered the same documents.

My question then is: How can I have only one set of these Pages documents without having duplicates?