[Jazzy Boomers]

I'm putting the sheet type in parentheses, the same song name, but I'm adding [Lyrics] or [Chords] [Key A], etc., after it.

The best thing would be to have a real setlist filter allowing the musician to see the correct score (transcription) displayed (Bb for brass, UT for singers, etc.). 
There are already requests for this, from music directors who provide the same score but in several transcription: UT, Bb, etc.
I think this is the right approach to follow. But the fact remains that to find your way around, you have to be systematic from the start. 
Each file name must be structured in the same way and methodically (uppercase, lowercase, spaces, etc.).

Exemple :

Setlist name : Concert Elvis xx.xx.2025

Song name in the Setils : Don't Be Cruel                Contains 3 files

Don't Be Cruel [Chord] Key A.pdf
Don't Be Cruel [Lyrics] Key A.pdf
Don't Be Cruel [Brass] Key A.pdf

If Mike proposes requests from "Music Directors", the filter in parentheses would allow the musician to display the correct sheet, even if his tablet contains the scores of all...