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.

Execution · Practiced Mastery
Coordinating two-man cover tactics and aggro swaps through scripted firefights.

Execution · Practiced Mastery
Patient ballistic aiming wrapped in plannable stealth positioning.
Army of Two: The 40th Day leans Execution (Practiced Mastery); Sniper Elite V2 leans Execution (Practiced Mastery).
Sniper Elite V2 leans a little harder on execution, though the gap is small.
Army of Two: The 40th Day
Cover shooting needs competent aim but generous systems forgive
Sniper Elite V2
Ballistics-compensated long shots demand steady precise aim
Same score on reads - which means the number cannot separate them. The difference is in what each one asks of you.
Army of Two: The 40th Day
Enemy AI is scripted, co-op partner cooperates rather than opposes
Sniper Elite V2
Enemy AI runs fixed alert routines
Same score on variance - which means the number cannot separate them. The difference is in what each one asks of you.
Army of Two: The 40th Day
Encounters are scripted with minor spawn unknowns first time
Sniper Elite V2
Wind and patrol details vary slightly per attempt
Same score on optimization - which means the number cannot separate them. The difference is in what each one asks of you.
Army of Two: The 40th Day
Aggro management and weapon upgrades reward planned coordination
Sniper Elite V2
Positioning, sound masking and route planning are learnable
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.