If leaving generals in cities didn't cause a nearly immediate breakdown of loyalty, common sense, and morality, I would consider it. As things currently stand, it seems the negative traits trigger quite easily, and beneficial ones never trigger for the most part (as far as being in a city anyway, even a highly developed city with academies and a University). So I manage em all til the system of using generals as mayors actually could benefit the ones assigned to building and empire management. In the meantime, generals are for fighting