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

Optimization · Practiced Mastery
The genre-defining 3D open-world crime game set in Liberty City.

Execution · Practiced Mastery
An open-world action sandbox about destabilising a dictatorship with parachute stunts.
Grand Theft Auto III leans Optimization (Practiced Mastery); Just Cause 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.
Grand Theft Auto III
Driving and clunky gunplay set a modest physical bar
Just Cause
Loose shooting and stunt vehicle control
Same score on reads - which means the number cannot separate them. The difference is in what each one asks of you.
Grand Theft Auto III
Enemies are scripted; nothing models the player
Just Cause
Soldiers follow dumb scripted AI
Same score on variance - which means the number cannot separate them. The difference is in what each one asks of you.
Grand Theft Auto III
Pedestrian and traffic chaos lightly randomises encounters
Just Cause
Open-world patrol noise, little hidden info
Grand Theft Auto III leans a little harder on optimization, though the gap is small.
Grand Theft Auto III
Mission routing and city knowledge are learnable systems
Just Cause
Liberation checklists and gear unlocks
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.