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

Execution · Practiced Mastery
A massive open-world sandbox built around grappling-hook and parachute chaos.

Optimization · Practiced Mastery
Wasteland open-worlder upgrading one car to conquer scripted scrap territories.
Just Cause 2 leans Execution (Practiced Mastery); Mad Max leans Optimization (Practiced Mastery).
Same score on execution - which means the number cannot separate them. The difference is in what each one asks of you.
Just Cause 2
Grapple-parachute flow rewards handling skill
Mad Max
Car combat and counter-brawling timing
Same score on reads - which means the number cannot separate them. The difference is in what each one asks of you.
Just Cause 2
Enemy AI never adapts
Mad Max
War boys follow fixed AI
Just Cause 2 leans a little harder on variance, though the gap is small.
Just Cause 2
Sandbox chaos varies moment to moment
Mad Max
Open world is static once scouted
Mad Max leans a little harder on optimization, though the gap is small.
Just Cause 2
Chaos-point economy and settlement completion routing
Mad Max
Magnum Opus upgrades and stronghold routing
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.