Ha, the AI is brutal. I'm doing a multi-class endurance race with heavy damage. It changes the game as the slightest brush with a wall screws up your suspension and down force. I've done many laps having to steer slightly one way to go straight lol.
Yet the most damage I have received and forced me to limp to the pit was from the AI rear ending me while I gave them plenty room to pass. The TS050 simply boosted into me in a braking zone. Engine damage, punted into the wall, wall penalty, front, back, all 4 wheels, everything blinking. The TS050 simply drove away. He was one lap behind as well, blue flag murder.
Maybe it's better to leave them on intermediate level and race against a higher class. Not that it matters, no clue why the TS050 fell a whole lap behind at pro level with me in the Sauber C9. He did set the fastest lap in one of his boost sessions.
No wonder the whole campaign is pass the docile moving pylons. As soon as you want to engage with them they are worse than SR.B dive bombers. And they respect the blue flag about as much as online players