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
An arcade-style flight combat game of aerial dogfights and ground strikes.
Grid 2 leans Execution (Practiced Mastery); Tom Clancy's H.A.W.X 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
Tom Clancy's H.A.W.X 2
flight control precision under time pressure
Grid 2 leans a little harder on reads, though the gap is small.
Grid 2
Online wheel-to-wheel adds light positional prediction
Tom Clancy's H.A.W.X 2
scripted enemy squadrons, not adaptive
Tom Clancy's H.A.W.X 2 leans a little harder on variance, though the gap is small.
Grid 2
Tracks are fixed and fully visible
Tom Clancy's H.A.W.X 2
some mission event randomness
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
Tom Clancy's H.A.W.X 2
loadout and maneuver routing
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.