These two dudes likely already knew they had a problem with each other.
Prior contact with management could have resulted in one or both retaining their job. In the absence of pre-settlement, one of them needed to call sick before take-off, to reduce the known risk. The first to "complain" or the F/O, is not automatically the one needing further training or dismissal.
Pre and post CRM I have requested to not fly with a couple of pilots and in another earlier case, while still an F/O on probation, I made it clear enough that I would not fly with an alcoholic captain who soon lost his job. In all these cases I am certain that actual military backgrounds was not a factor.
It is hard to risk a job, built up security and seniority for principles. It has always turned out that it is not that I refuse, but how I approach my company to solve a safety problem.
Crew management is not just CRM. Every contact with cockpit and cabin crew members should be with a thought at the back of the mind that you would, by example, encourage them to walk on burning coals for a safe flight. Just part of the job, like proper rest, check rides, sim, studying FOM etc.
Sometimes, as an expat, there may be cultural considerations that prevent your best efforts resulting in a sufficiently safe flight. The choice may be to resign or stick to your minimum safe principles and risk dismissal.