. I suppose you *might* find that a particular group is underrepresented because many of them are pacifists, in which case there's probably not much you can do, but otherwise if your cohort isn't representative of the general population it probably points to a problem somewhere; either you're missing out on applicants or people are leaving because the environment doesn't welcome them. But you fix that problem at source, not by counter-discriminating during the selection process.
Introducing ethnicity/skin color/etc as a factor during selection is indeed discriminating.
The selection process should be on merit alone, everything else is irrelevant.