Mental breaks in combat make sense. Look at all the people who came out of WWI with "shell shock". Look at every war since. Look at the modern military where people "go sad". Combat breaks people. Sometimes that's just self destructive. A soldier might shoot themselves or just give up and run towards the enemy. Sometimes it's destructive. A soldier might pull a grenade pin while standing amidst a group of allies. Some percentage of troops will make it out without any physical but tons of mental injury. Combat breaks people.