Since he can create several files in a short interval, so that even Time::HiRes isn't updated quickly enough (update interval is 18 times a second, on Windows), and the resolution of creation date is in general only 1 or 2 seconds, I am certain you haven't solved the OP's problem

I am less certain of your certainty ;-)

The OP apparently has multiple processes running that are dumping these files (my emphasis):

command line interface gets called extremely often and often several for these processes run at the same time

Which was why I said:

(I'm assuming that your comments about multiple processes mean that the exact order isn't important.)

The exact running order is going to be dependent on a lot of factors outside the OPs control. Depending on the exact requirements having unique filenames and a rough order may well be enough.