[Chris is me]

My driver testing theory I break down into teams that can practice for at least a week, and teams that can't.

For teams that don't have practice resources, throw all the driver candidates behind the controls for an hour or so and have a group consisting of the drive coach and other non-drive team parties decide who's best. Eliminate obviously uncooperative people who would not make mature drivers though.

For teams that can practice for a week or more, team leadership should pick drivers before they even touch the controls. Maybe even before Kickoff. Nearly anyone can be trained to be a good driver, but few can be trained to be a mature driver that stays cool under pressure. A pair of students that are the most mature and level headed that work well with the coach should be selected and practice should be done early and often.

This is all my opinion, and disclaimer, I've never trained a group of drivers or anything. Working on 1714 as a tactician, the drivers on my team were already fantastic and I had no part in picking or training them or anything.