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.

Optimization · Practiced Mastery
The original European trucking sim of long hauls and tidy deliveries.

Execution · Practiced Mastery
Linear postwar crime story driven by cover shootouts and atmosphere.
Euro Truck Simulator leans Optimization (Practiced Mastery); Mafia II leans Execution (Practiced Mastery).
Mafia II leans a little harder on execution, though the gap is small.
Euro Truck Simulator
Basic truck handling and parking
Mafia II
Cover shooting and fistfight timing
Same score on reads - which means the number cannot separate them. The difference is in what each one asks of you.
Euro Truck Simulator
No adaptive opposition
Mafia II
Enemies are scripted
Same score on variance - which means the number cannot separate them. The difference is in what each one asks of you.
Euro Truck Simulator
Minor traffic variation
Mafia II
Story missions are fixed
Same score on optimization - which means the number cannot separate them. The difference is in what each one asks of you.
Euro Truck Simulator
Delivery routes and truck upgrades
Mafia II
Modest; learning encounter layouts
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.