If you find yourself in a survival scenario, one thing you’re going to have to deal with is stress. Everyone reacts differently to stressful situations. Some shine, some not so much. Group cohesiveness is imperative here. The last thing you need is for a member to loose control. While it is difficult to replicate the stress of an all out survival situation, you can turn up the heat a bit. Put your group through a series of bug out drills, culminating in a weekend stay in the field. Run full group survival discipline. Watch each member closely for signs of cracking under the pressure. Once you return to the real world you will have to make a difficult decision. If someone breaks under a mere simulation, they need to be removed from the group at once and replaced. The groups survival depends on this. A loose canon within endangers you all.