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

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

Execution · Practiced Mastery
A cinematic Victorian cover shooter about knights hunting half-breeds with exotic weaponry.
Mafia II leans Execution (Practiced Mastery); The Order: 1886 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
The Order: 1886
Standard cover shooting with quick-time events
The Order: 1886 leans a little harder on reads, though the gap is small.
Mafia II
Enemies are scripted
The Order: 1886
Scripted setpiece enemies
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
The Order: 1886
Heavily authored, nothing 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
The Order: 1886
Linear encounters, light tactical layer
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.