head to head
Neither is harder. They score identically on all four axes, so the difference between them is in kind, not degree.

Execution · Practiced Mastery
Linear postwar crime story driven by cover shootouts and atmosphere.

Execution · Practiced Mastery
A deliberately paced shooter testing easy aim and light build choices in scripted missions.
Mafia II leans Execution (Practiced Mastery); RoboCop: Rogue City 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.
Mafia II
Cover shooting and fistfight timing
RoboCop: Rogue City
Deliberate aiming with a tanky hero, light demands
Same score on reads - which means the number cannot separate them. The difference is in what each one asks of you.
Mafia II
Enemies are scripted
RoboCop: Rogue City
Criminal AI runs simple fixed scripts
Same score on variance - which means the number cannot separate them. The difference is in what each one asks of you.
Mafia II
Story missions are fixed
RoboCop: Rogue City
Linear missions hold little hidden or random
Same score on optimization - which means the number cannot separate them. The difference is in what each one asks of you.
Mafia II
Modest; learning encounter layouts
RoboCop: Rogue City
Skill points and pistol upgrades structure modest build planning
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.