You're absolutely right. So take my Noah's ark idea. Would you not only grab the best of the best? Someone with exceptional skills, in one direction or another, who could leave your ark better than it was when they got there?
Perhaps further, the ark is for a restarting of man kind, re-evolution if you will. The species of different times have been dropped together into the ark, and all the ark is would be a sort of petri dish. All the people from different times that are constantly referenced are just different cultures added for the sake of continued evolution.