No, Bush's AG did not bind prosecutors to effectively always settle corporate cases without convictions. Following high-profile corporate scandals (e.g., Enron, WorldCom, Tyco), Bush established the Corporate Fraud Task Force in 2002. Over the next couple of years the DOJ obtained over 500 corporate fraud convictions or guilty pleas. They charged over 900 defendants and over 60 corporate CEOs and presidents with some type of corporate fraud crime in connection with over 400 filed cases.
https://www.justice.gov/archive/opa/pr/2004/July/04_dag_495....