At the arraignment, the Magistrate Judge assigned to a case typically sets dates by which pretrial motions and any plea agreement must be filed, and schedules the final pretrial conference and trial.
The Magistrate Judge ordinarily holds the final pretrial conference.
Judge Simon conducts plea hearings.
Because multiple trials are scheduled on the same day, criminal cases will be assigned a setting (e.g., primary setting, secondary setting, etc.). If there is a conflict, cases will usually be rescheduled according to that order.