head to head
Grand Theft Auto V asks more than Will Rock, and the gap is reads.

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

Execution · Practiced Mastery
A Serious Sam-style horde shooter testing strafing aim against scripted waves.
Grand Theft Auto V leans Execution (Practiced Mastery); Will Rock leans Execution (Practiced Mastery).
Will Rock leans a little harder on execution, though the gap is small.
Grand Theft Auto V
Driving and shooting demand decent inputs.
Will Rock
Circle-strafing huge enemy swarms is the whole test
Grand Theft Auto V leans clearly harder on reads.
Grand Theft Auto V
Online PvP exists but mostly gear/positioning, not modeling.
Will Rock
Monsters charge in fixed spawned waves
Grand Theft Auto V leans a little harder on variance, though the gap is small.
Grand Theft Auto V
Some mission and lobby randomness.
Will Rock
Spawns are scripted and repeat identically
Same score on optimization - which means the number cannot separate them. The difference is in what each one asks of you.
Grand Theft Auto V
Heists, money loops, builds learnable.
Will Rock
Weapon choice and arena positioning are learnable
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.