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 · Practiced Mastery
A gritty WWII Call of Duty that introduced the Zombies mode.

Execution · Pure Mechanics
An arcade-style soccer simulation with licensed national teams.
Call of Duty: World at War leans Execution (Practiced Mastery); World Tour Soccer 2002 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: World at War
Twitch gunfights in fast multiplayer lobbies
World Tour Soccer 2002
player control, passing and shooting precision
Same score on reads - which means the number cannot separate them. The difference is in what each one asks of you.
Call of Duty: World at War
Human opponents reward positioning prediction
World Tour Soccer 2002
opponent play in human matches adds reads
Call of Duty: World at War leans a little harder on variance, though the gap is small.
Call of Duty: World at War
Random lobbies, spawns, and zombie waves
World Tour Soccer 2002
minor bounce/ref randomness
Call of Duty: World at War leans a little harder on optimization, though the gap is small.
Call of Duty: World at War
Perk loadouts and map control are learnable
World Tour Soccer 2002
tactics and formation choices 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.