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

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

Execution · Practiced Mastery
A cinematic open-world western leaning on shooting feel and atmosphere.
Cars leans Execution (Practiced Mastery); Red Dead Redemption 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.
Cars
Forgiving kart-style driving with modest racing line demands
Red Dead Redemption 2
Gunplay and Dead Eye reward aim and 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
Red Dead Redemption 2
Enemies use scripted AI patterns, not adaptation.
Red Dead Redemption 2 leans a little harder on variance, though the gap is small.
Cars
Tracks and events are fixed once seen
Red Dead Redemption 2
Some hunting and weather randomness, lightly hidden.
Red Dead Redemption 2 leans a little harder on optimization, though the gap is small.
Cars
Learning racing lines and shortcuts gives most of the edge
Red Dead Redemption 2
Loadouts and routes solvable but loose.
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.