“Military supervisor hat on”: Get all invested parties together and hash it out, moderated by an objective 3rd party (generally another NCO) that can be impartial in the matter. And try to make this a growing experience for everyone.
However, in the military, this would have happened when the issue was first affected the workplace (which would have been months ago), before everyone was more embittered.
But, this is nixpkgs, people live in different timezones and aren’t obligated to get along with anyone. In the military, you don’t choose your coworkers/soldiers/subordinates/supervisors, but you still have to work with them; so there’s a high premium in dealing with personal issues quickly. Also, you’re incentived to get along with people when there’s a possibility to be deployed with them and they are carrying firearms.
EDIT: wording