head to head
Grand Theft Auto: San Andreas asks more than One Piece: Pirate Warriors 4, and the gap is optimization.

Optimization · Practiced Mastery
A sprawling open-world crime epic with RPG-style character stats across a whole state.

Execution · Practiced Mastery
A musou-style hack-and-slash letting players mow down hordes as One Piece characters.
Grand Theft Auto: San Andreas leans Optimization (Practiced Mastery); One Piece: Pirate Warriors 4 leans Execution (Practiced Mastery).
One Piece: Pirate Warriors 4 leans a little harder on execution, though the gap is small.
Grand Theft Auto: San Andreas
Flying school and drive-bys need decent hands
One Piece: Pirate Warriors 4
crowd-clearing combo execution against hordes
One Piece: Pirate Warriors 4 leans a little harder on reads, though the gap is small.
Grand Theft Auto: San Andreas
Gang AI is scripted, never adaptive
One Piece: Pirate Warriors 4
enemies are scripted mobs, not adaptive
Grand Theft Auto: San Andreas leans a little harder on variance, though the gap is small.
Grand Theft Auto: San Andreas
Territory wars and traffic add light randomness
One Piece: Pirate Warriors 4
minimal randomness in stage encounters
Grand Theft Auto: San Andreas leans clearly harder on optimization.
Grand Theft Auto: San Andreas
Stats, gym, weapon skill, and routes reward systematic play
One Piece: Pirate Warriors 4
character builds and combo routing 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.