My librarians aren't resetting their trades when I destroy their job blocks and they wouldn't lose their jobs when I destroy their blocks. I had no choice but to murder them in order to get them to their jobs aligned correctly. I try to make sure to avoid hitting the ones that are ranked up. When I do use my monorail system to get to them the game wouldn't let me destroy their job block to reset their trades to look for the ones that I'm looking for. They still have their librarian clothes on and their previous trades.