head to head
Neither is harder. They score identically on all four axes, so the difference between them is in kind, not degree.

Execution · Practiced Mastery
A gentle licensed racer testing basic driving lines against scripted opponents.

Execution · Practiced Mastery
Cinematic treasure-hunting where set pieces outshine systems.
Cars leans Execution (Practiced Mastery); Uncharted 4: A Thief's End 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.
Cars
Forgiving kart-style driving with modest racing line demands
Uncharted 4: A Thief's End
Cover shooting and platforming reward timing.
Same score on reads - which means the number cannot separate them. The difference is in what each one asks of you.
Cars
AI racers follow rubber-band scripts; split-screen rivals barely adapt
Uncharted 4: A Thief's End
Scripted enemy AI throughout.
Same score on variance - which means the number cannot separate them. The difference is in what each one asks of you.
Cars
Tracks and events are fixed once seen
Uncharted 4: A Thief's End
Essentially no randomness.
Same score on optimization - which means the number cannot separate them. The difference is in what each one asks of you.
Cars
Learning racing lines and shortcuts gives most of the edge
Uncharted 4: A Thief's End
Few systems to optimize beyond difficulty.
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.