Villagers are not always arranged in the same order in the Details Screen rotation, and it's not uncommon to see them change positions. It, of course, is most noticeable when you give your villagers numbers for names (which I have done trying to track down the other part of your complaint).

The name-change issue is due to an elusive glitch, which is also in the first VV game, that we have been unable to locate and correct. The only thing you can do is to manually change the duplicated names back to what they were (or to a different name). If we can find and fix the problem, we will include the fix in an updated release of the game.