There are two issues here. Firstly, in Surveyor mode in the Driver Setup Rule, there is no way to move drivers up or down the order list (a short coming that has been noted by others). In the past the driver that was at the top of that list was the driver (and her/his consist) that had the camera focus when the route/session was started in Driver mode. Now, in TRS19, there is an additional option in the Driver Setup Rule, the "Focus camera on first driver" setting. When NOT ticked, this will give the camera focus in Driver mode to the driver that last had the focus when the session was saved in Surveyor (at least that has been my impression with some limited experience only).
Secondly, when in Driver mode, opening the driver list will display the drivers in the same order as they exist in the Driver Setup Rule. Again, there is no way that I know of to alter this order.