I think the closer the cars are to each other, the more unstable the gameplay becomes.
As the drivers get closer in the corners it is common to see cars being pushed back losing 1-2 positions unrealistically,
as well as visibly seeing a car overtake from a considerable distance. This problem is evident at the beginning of the races, taking an example of identical cars one could gain 10 positions and the other lose 10.
I already suggested revisiting the overtaking system but that is not as unfair and unbalanced as this.