head to head
Neither is harder. They score identically on all four axes, so the difference between them is in kind, not degree.

Execution · Pure Mechanics
WWII gunfight execution with light multiplayer prediction.

Execution · Pure Mechanics
Modern-military shooting execution with a light multiplayer prediction layer.
Call of Duty 3 leans Execution (Pure Mechanics); Medal of Honor 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 3
Aimbot trivialises both campaign and multiplayer gunfights
Medal of Honor
Aimbot trivialises both scripted campaign and multiplayer firefights
Same score on reads - which means the number cannot separate them. The difference is in what each one asks of you.
Call of Duty 3
Multiplayer adds modest human positional prediction
Medal of Honor
Human multiplayer lobbies add modest prediction
Same score on variance - which means the number cannot separate them. The difference is in what each one asks of you.
Call of Duty 3
Scripted setpieces and spawn flow add minor unknowns
Medal of Honor
Scripted ambushes are unknown only on first contact
Same score on optimization - which means the number cannot separate them. The difference is in what each one asks of you.
Call of Duty 3
Map knowledge and weapon choice reward light study
Medal of Honor
Map and loadout knowledge add a light planning layer
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.