A few sentences in the article mention that Stengel let some people go when he took office, but the rest of it is written like it's unusual for them to be fired. Political appointees serve at the pleasure of the politician who hired them. They are not merit employees. I wouldn't expect someone who ran against the winner to keep his job when he lost. If you take office and keep all of the last guy's appointees in charge, then you're not very serious about improving your agency (As seen in LMPD)