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 · Grand Arena
Fast arena shooter with deep loadout tuning.

Execution · Pure Mechanics
Classic arena aim married to champion abilities, tested against adaptive human opponents in fast duel maps.
Call of Duty: Modern Warfare III leans Execution (Grand Arena); Quake Champions 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.
Call of Duty: Modern Warfare III
Fast TTK punishes any aim error
Quake Champions
Champion abilities add execution layers on top of classic rail and rocket aim
Same score on reads - which means the number cannot separate them. The difference is in what each one asks of you.
Call of Duty: Modern Warfare III
Sliding and pre-aim duels reward prediction
Quake Champions
Human duels require reading opponent ability usage and positioning
Same score on variance - which means the number cannot separate them. The difference is in what each one asks of you.
Call of Duty: Modern Warfare III
Spawn flips and map traffic add noise
Quake Champions
Ability cooldowns introduce mild timing uncertainty per match
Call of Duty: Modern Warfare III leans a little harder on optimization, though the gap is small.
Call of Duty: Modern Warfare III
Loadouts, perks, attachments heavily tuned
Quake Champions
Champion matchup knowledge and item timing are solvable advantages
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.