head to head
Grid 2 asks more than Grand Theft Auto V, and the gap is execution.

Execution · Practiced Mastery
Sandbox crime playground spanning shooting, driving, and a persistent online economy.

Execution · Practiced Mastery
Cornering execution over memorisable circuits, with light prediction in wheel-to-wheel multiplayer.
Grand Theft Auto V leans Execution (Practiced Mastery); Grid 2 leans Execution (Practiced Mastery).
Grid 2 leans clearly harder on execution.
Grand Theft Auto V
Driving and shooting demand decent inputs.
Grid 2
Car control through corners is the entire moment-to-moment test
Same score on reads - which means the number cannot separate them. The difference is in what each one asks of you.
Grand Theft Auto V
Online PvP exists but mostly gear/positioning, not modeling.
Grid 2
Online wheel-to-wheel adds light positional prediction
Grand Theft Auto V leans a little harder on variance, though the gap is small.
Grand Theft Auto V
Some mission and lobby randomness.
Grid 2
Tracks are fixed and fully visible
Grid 2 leans a little harder on optimization, though the gap is small.
Grand Theft Auto V
Heists, money loops, builds learnable.
Grid 2
Racing lines, braking points and car selection are studyable
A matching score does not mean a matching test. Two games can both sit at 10 on execution and demand completely different things of you - which is why the reasoning above matters more than the number beside it.