Are you kidding me? Aggressive, unstable and destructive seem to be core tenants for the CEOs of many large scale blue chip firms.
If you want actual penetration defense, you absolutely hire the unstable person. I'm not saying you put him or her in the centre desk on the main floor, let him or her work from an environment where they are most comfortable, and one that supports them best.
If you want window dressing, hire the neat and tidy person, who couldn't actually penetrate an Excel sheet.