The combination of power and down force should mean the AMG should be a lot quicker.
It's just a simulation, at the end of the day
I generally put it down to tyres.
When they tested the P1, 918, LaFerrari combo at Silverstone National circuit all three were slower than a BTCC Ford Focus of that era too.
The disparity between what a fairly simple car can do on racing slicks at most circuits, and what a massively over-engineered multi-million pound hype-car can do is one of the main reasons why I don't get that excited by this class of car.