Military training changed after the Vietnam War. Up to that point, in all wars, 90% of the killing was done by 10% of the soldiers. Most just did what they had to do to survive and go back home because killing isn't a natural instinct. With the disaster of the '60s draft, the Pentagon knew they had to do more in the future with fewer soldiers. The answer was to mold them into killing machines that don't hesitate for a second to end the conflict.
Beginning by taking only volunteers, they knew they were halfway to a more efficient army with a higher kill ratio because the enlistees wanted to be there. More intense training and sorting out the psychologically callous for special forces created an army that the world has never seen through history. It's also the most expensive.
Sometimes one of those killing machines go offline. They lose touch with the real world and require a reboot or worse. Unfortunately, that faulted unit is connected to his comrades in the brotherhood and that makes punishment a dicey proposition. Morale is the biggest asset of an effective army.
Anyway, it's the ingrained brotherhood of the soldier that is now forming a protective wall around this particular defected unit. It would be like turning in a blood family member.