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.

Optimization · Practiced Mastery
Grim stealth horror about luring scripted hunters into executions.
Army of Two: The 40th Day leans Execution (Practiced Mastery); Manhunt leans Optimization (Practiced Mastery).
Army of Two: The 40th Day 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
Manhunt
Stealth timing on executions
Army of Two: The 40th Day leans a little harder on reads, though the gap is small.
Army of Two: The 40th Day
Enemy AI is scripted, co-op partner cooperates rather than opposes
Manhunt
Hunters patrol on scripts
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
Manhunt
Patrol noise reactions add small unpredictability
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
Manhunt
Shadow routes and lure tactics 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.