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

Execution · Practiced Mastery
The trilogy capper with the series' most polished competitive multiplayer.

Execution · Pure Mechanics
A PS4-era Killzone where a Shadow Marshal and his OWL drone fight through a divided Helghast city.
Gears of War 3 leans Execution (Practiced Mastery); Killzone Shadow Fall leans Execution (Pure Mechanics).
Same score on execution - which means the number cannot separate them. The difference is in what each one asks of you.
Gears of War 3
Refined wallbounce and gnasher precision dominate versus
Killzone Shadow Fall
Standard FPS aim and movement ceiling
Same score on reads - which means the number cannot separate them. The difference is in what each one asks of you.
Gears of War 3
Reading human rotations and bait plays matters
Killzone Shadow Fall
PvP modes reward predicting human players
Same score on variance - which means the number cannot separate them. The difference is in what each one asks of you.
Gears of War 3
Horde waves vary slightly
Killzone Shadow Fall
Some open level routes and spawn noise
Gears of War 3 leans a little harder on optimization, though the gap is small.
Gears of War 3
Map spawns and loadout meta are mappable
Killzone Shadow Fall
OWL drone usage and loadouts optimize cleanly
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.