FCP Media Import and Organizational Question

If you already have your contributors set up with Keyword collections, all you need to do to add to them is select their clips from the Finder and drag them ONTO the Keyword collection label in the Event browser. If you are dropping duplicate (named) media onto the keyword, FCP won't duplicate it (AFAICT, FCP will ignore the duplicates and previously applied Notes/Meta seem to stay intact).

As a general rule, it is important not to import files with duplicate names. One of the simplest and most important steps in media organization (with any NLE, not just FCP) is to ensure the filenames are globally unique across all time and all projects.

One easy way is fast, easy and requires no thought is appending a 4 or 5-digit incremental serial number to each batch of offloaded files. Finder's batch rename function will do that, but you must keep track of the highest serial number used, then start the next batch rename operation using +1 of that.

For specifics, in YouTube query on "Batch Rename Multiple Files On a Mac"

I discussed other aspects of media management here: 256233840

And here: 256245553

There are other more elaborate file renaming systems, but those take time, planning and attention to "data dictionary" issues. E.g, you need predefined consistent terms. Example:

YEAR_PROJNAME_CITY_EVENT_DETAILS_CAMA/B/C_REEL_SHOT_TAKE_SHOOTERINITIALS.mp4

If you permit duplicate filenames, FCP attempts to handle that by internally appending a "uniquifier" inside the library such as (fcp1), (fcp2), etc. But the logical filenames you see within FCP will be duplicates. If you import three files named c0001.mp4, then search on "c0001," it will return three files, not one file.

This can later cause major problems if you ever need to relink media. Duplicate filenames can cause other side effects if you ever copy a multicam or compound clip between libraries.

You can also highlight a keyword collection and use the Import window. It’ll put them directly into the selected container. But I usually drag and drop, like fox says.

PS - Test this (a clip with added metadata) with ONE clip first to make sure it doesn't get overwritten.

I'm still in FCP 10.4.10, and so my recommendation may depend on the version.