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

Execution · Pure Mechanics
An asymmetric FPS with three interlocking campaigns as marine, alien, and predator on the same colony.

Execution · Practiced Mastery
A gritty WWII Call of Duty that introduced the Zombies mode.
Aliens vs. Predator 2 leans Execution (Pure Mechanics); Call of Duty: World at War 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.
Aliens vs. Predator 2
Wall-crawling aliens and panicked marines test raw aim
Call of Duty: World at War
Twitch gunfights in fast multiplayer lobbies
Same score on reads - which means the number cannot separate them. The difference is in what each one asks of you.
Aliens vs. Predator 2
Cross-species multiplayer rewards outguessing human opponents
Call of Duty: World at War
Human opponents reward positioning prediction
Aliens vs. Predator 2 leans a little harder on variance, though the gap is small.
Aliens vs. Predator 2
Motion tracker pings and dark corridors conceal threats
Call of Duty: World at War
Random lobbies, spawns, and zombie waves
Call of Duty: World at War leans a little harder on optimization, though the gap is small.
Aliens vs. Predator 2
Species matchup knowledge and map control are learnable
Call of Duty: World at War
Perk loadouts and map control are learnable
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.