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
Heavy first-person gunplay testing aim, with positional prediction in multiplayer.

Execution · Competitive PvP
A soccer game testing on-pitch execution and outplaying opponents.
Killzone 3 leans Execution (Pure Mechanics); This is Football leans Execution (Competitive PvP).
Killzone 3 leans a little harder on execution, though the gap is small.
Killzone 3
Weighty gunplay still demands aim and recoil control
This is Football
Passing, shooting, and movement timing drive matches
Same score on reads - which means the number cannot separate them. The difference is in what each one asks of you.
Killzone 3
Multiplayer opponents flank and bait; campaign AI is scripted
This is Football
Human opponents you outmaneuver; AI is scripted
This is Football leans a little harder on variance, though the gap is small.
Killzone 3
Spawns and spread inject limited randomness
This is Football
Some ball-physics and AI randomness
Same score on optimization - which means the number cannot separate them. The difference is in what each one asks of you.
Killzone 3
Map control, loadouts and class roles structure multiplayer
This is Football
Tactics, formations, and squad management matter
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.