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

Execution · Pure Mechanics
The 70s-cinema getaway driving game with famously demanding physics.

Execution · Practiced Mastery
Precise stunt driving over loops and jumps plus route optimisation per track.
Driver leans Execution (Pure Mechanics); Stunts 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.
Driver
Handbrake control and pursuit driving by feel
Stunts
Threading loops and jumps without crashing demands precise driving
Same score on reads - which means the number cannot separate them. The difference is in what each one asks of you.
Driver
Police AI is mappable
Stunts
AI opponents follow fixed lines
Same score on variance - which means the number cannot separate them. The difference is in what each one asks of you.
Driver
Traffic adds mild unpredictability
Stunts
Tracks are known; physics quirks barely random
Stunts leans a little harder on optimization, though the gap is small.
Driver
City routes and mission tactics learnable
Stunts
Optimal lines and car choice per track are solvable
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.