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
A licensed brawler testing combat timing and memorised boss patterns.

Execution · Practiced Mastery
Sandbox crime playground spanning shooting, driving, and a persistent online economy.
Dragon Ball: Revenge of King Piccolo leans Execution (Practiced Mastery); Grand Theft Auto V leans Execution (Practiced Mastery).
Dragon Ball: Revenge of King Piccolo leans a little harder on execution, though the gap is small.
Dragon Ball: Revenge of King Piccolo
Combo timing and platforming reflexes carry the levels
Grand Theft Auto V
Driving and shooting demand decent inputs.
Grand Theft Auto V leans a little harder on reads, though the gap is small.
Dragon Ball: Revenge of King Piccolo
Bosses run scripted patterns, never adapt
Grand Theft Auto V
Online PvP exists but mostly gear/positioning, not modeling.
Grand Theft Auto V leans a little harder on variance, though the gap is small.
Dragon Ball: Revenge of King Piccolo
Level content is fixed after one playthrough
Grand Theft Auto V
Some mission and lobby randomness.
Same score on optimization - which means the number cannot separate them. The difference is in what each one asks of you.
Dragon Ball: Revenge of King Piccolo
Learning boss movesets and stage routes is the rest
Grand Theft Auto V
Heists, money loops, builds 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.