Mental conditioning. Alicia/Beth knows nothing but how to awaken, how to return to human form, and how to kill the enemy. Not enough intellect to think for herself. As for the others, they send the ones they feel are threats on tough missions to decrease their life expectancy; should they fail to comply, they are branded traitors and executed by those still loyal. As it stands in the manga, though, things stand to get mighty interesting on that front.