The Schwartzian Transform is obviously a requirement for this - what if a file is deleted and re-created in the middle of the sort? That would translate into inconsistent results - and you also make a lot less of OS calls.

Of course, this doesn't address the problem of having the bunch of files changed after you've -M'ed them.

Since this seems to be a live directory, you should be especially careful of what you are dropping there or you might shoot yourself in the foot.