I have an idea of a new staff member. The coach. The coach would influence the driver’s training. And you could contract retired drivers to become coaches, the better their stats has driver. The better they would be has coaches.
The other staff would be the pit team. He would impact your pits time. And the pit time would be relative to the track/pit team level. No more in the same track someone getting 4.5 seconds pit and you getting 4.9 randomly.