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 · Pure Mechanics
A futuristic Call of Duty whose exoskeleton boosts made aerial movement king.

Execution · Practiced Mastery
The sequel adding Horde mode to the campaign-plus-versus cover shooter formula.
Call of Duty: Advanced Warfare leans Execution (Pure Mechanics); Gears of War 2 leans Execution (Practiced Mastery).
Call of Duty: Advanced Warfare leans a little harder on execution, though the gap is small.
Call of Duty: Advanced Warfare
Exo boost-dodging raises the mechanical ceiling sharply
Gears of War 2
Gnasher battles and movement tech set the ceiling
Same score on reads - which means the number cannot separate them. The difference is in what each one asks of you.
Call of Duty: Advanced Warfare
Predicting human boost paths wins gunfights
Gears of War 2
Human opponents in versus drive prediction play
Call of Duty: Advanced Warfare leans a little harder on variance, though the gap is small.
Call of Duty: Advanced Warfare
Spawns and supply-drop loot add randomness
Gears of War 2
Horde spawns add mild randomness
Same score on optimization - which means the number cannot separate them. The difference is in what each one asks of you.
Call of Duty: Advanced Warfare
Movement tech and class builds are learnable
Gears of War 2
Power-weapon timing and positioning are solvable
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.