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

Execution · Practiced Mastery
Sandbox crime playground spanning shooting, driving, and a persistent online economy.

Execution · Practiced Mastery
Bleak road-trip shooter where every weapon levels up through use.
Grand Theft Auto V leans Execution (Practiced Mastery); Resistance 3 leans Execution (Practiced Mastery).
Resistance 3 leans a little harder on execution, though the gap is small.
Grand Theft Auto V
Driving and shooting demand decent inputs.
Resistance 3
Precision shooting with health pickups punishing sloppy play.
Same score on reads - which means the number cannot separate them. The difference is in what each one asks of you.
Grand Theft Auto V
Online PvP exists but mostly gear/positioning, not modeling.
Resistance 3
Mostly scripted campaign; smaller multiplayer scene.
Same score on variance - which means the number cannot separate them. The difference is in what each one asks of you.
Grand Theft Auto V
Some mission and lobby randomness.
Resistance 3
First-run encounter unknowns.
Resistance 3 leans a little harder on optimization, though the gap is small.
Grand Theft Auto V
Heists, money loops, builds learnable.
Resistance 3
Weapon-leveling wheel rewards deliberate arsenal investment.
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.