Victor
Level 20 employees are rare to find, but a level 19 5 * corresponds to a level 20.
Thanks mate
Frank
Yes, it's same for everyone, but level 20 is the (main) exception to the rule that you need same level staff for optimal result. As Victor wrote 5 star level 19 staff also works fine.
For drivers level doesn't matter for pace, for them level just slows training and raises cost and/or selling value, but if you still want level 20 you need a not fully trained talent 20 driver and leave him not fully trained, usually with the last Mental stat at 19, until he gathered 20 experience and only then complete training.
That makes sense know thought I was the only one