head to head
Neither is meaningfully harder - they pose close to the same test. The widest gap is reads, and it is a single point.

Execution · Practiced Mastery
Cornering execution over memorisable circuits, with light prediction in wheel-to-wheel multiplayer.

Execution · Practiced Mastery
Arcade car control at speed over memorised tracks with scripted police pressure.
Grid 2 leans Execution (Practiced Mastery); Need for Speed: Hot Pursuit 2 leans Execution (Practiced Mastery).
Same score on execution - which means the number cannot separate them. The difference is in what each one asks of you.
Grid 2
Car control through corners is the entire moment-to-moment test
Need for Speed: Hot Pursuit 2
High-speed cornering and traffic dodging are the whole test
Grid 2 leans a little harder on reads, though the gap is small.
Grid 2
Online wheel-to-wheel adds light positional prediction
Need for Speed: Hot Pursuit 2
AI racers and cops follow rubber-band scripts
Need for Speed: Hot Pursuit 2 leans a little harder on variance, though the gap is small.
Grid 2
Tracks are fixed and fully visible
Need for Speed: Hot Pursuit 2
Cop spawns and traffic add mild run-to-run noise
Same score on optimization - which means the number cannot separate them. The difference is in what each one asks of you.
Grid 2
Racing lines, braking points and car selection are studyable
Need for Speed: Hot Pursuit 2
Track knowledge and racing lines are learnable and fixed
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.