[ivanhoe]

Why do you presume that all people from the same place are automatically friends or even like each other? When you have people with histories there's camaraderie, but there are also rivalries, stolen girlfriends, family disputes, revenges, all kinds of histories and skeletons in the closet that can cause problems later on. On the other hand, starting on a clean slate avoids this - and in my own experience at least, spending 3+ months in a bootcamp 24/7, eating, training and sleeping with the same guys creates by itself quite a strong bonds between people and a sense of brotherhood (united against the officers mostly, but still the brotherhood).