[Geoff Bacon]

I would add the name of the group to each filename e.g.
Bad Moon Rising [G] - Group1.pdf
Bad Moon Rising [G] - Group2.pdf
Bad Moon Rising [G] - Group3.pdf
(choose Group1, 2 and 3 to suit).

This guarantees that the file names are different 
There are free programs on the web that can add a suffix to all files in a windows directory (google "renaming files with a suffix")

Having separate names means that you don't have to worry about changes in one group affecting another.

However, you do need to maintain this naming format when downloading other songs (so keep your group names short! e.g. Pub)

When importing, in the Import Settings dialog, set Title (top of display) to "Use Filename As Title" (rather than Guess)
If you use Guess, you will get a spurious space character after certain letters/digits

I do all my preparation on a windows pc and use the Companion to import them to the tablet

Suggest you play around with a few songs to establish how it all works then clear the library and load it up for real.

If you will be putting a lot of files on the tablet then I suggest you turn off automatic updating of MobileSheets.
When an update is available, use the Companion to take a backup to your windows pc before performing the manual backup.

This means that you have a backup of the latest files on your windows pc should there be an issue with the update (it has been known)
Manual updates also means that you don't get an unexpected update immediately prior to a gig

Geoff