If it never has more than 10 files, who cares? If it's fast enough, don't worry. if you need more speed, benchmark and profile.

Except that sorting N values involves N log N to N^2 comparisons, and if each comparison involves 2 stat, at 10 ms each, it does waste system resources. Schwartzian Transform - creating a hash which associates the stat time with the file name - involves only N stats, and would be economical.

If files are not going to change, keep a list of known files in a hash, and obtain a list of eligible files. If there are any new files, stat only the ones you don't already know about.