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 · Competitive PvP
Modern-military 64-player shooter where squads, commanders, and vehicles contest sprawling conquest maps.

Execution · Practiced Mastery
The sequel adding Horde mode to the campaign-plus-versus cover shooter formula.
Battlefield 2 leans Execution (Competitive PvP); Gears of War 2 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.
Battlefield 2
Aim, jet and chopper piloting, infantry movement
Gears of War 2
Gnasher battles and movement tech set the ceiling
Battlefield 2 leans a little harder on reads, though the gap is small.
Battlefield 2
Squads and commanders out-maneuver human opposition
Gears of War 2
Human opponents in versus drive prediction play
Battlefield 2 leans a little harder on variance, though the gap is small.
Battlefield 2
Spawn timing and vehicle contention add noise
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.
Battlefield 2
Flag rotation, class roles, and commander assets
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.