As i see in forums threads and my friends comments , raising difficulty not making them a better driver but making drivatar cars more powerful than cars actual stats . My friend said he tried pro difficulty and drivatar cars became magically faster in straights . And in unbeatable lol he said they are “unbeatable” . He said they were becoming dom(ff reference) in straights , senna in turns even theres rain and T-800 in corners(trying to say they ramming you like you were not there) . So as i understand its just make the car powerful and better beyond cars actual stats .