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
High-volume shooting accuracy through chaotic scripted raids.

Execution · Pure Mechanics
WWII shooter remembered for its Omaha Beach landing and tense rifle duels.
Delta Force: Black Hawk Down leans Execution (Pure Mechanics); Medal of Honor: Allied Assault 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.
Delta Force: Black Hawk Down
Fast aim against dense hostile crowds is the core test
Medal of Honor: Allied Assault
classic FPS aim, leaning, and sniping
Same score on reads - which means the number cannot separate them. The difference is in what each one asks of you.
Delta Force: Black Hawk Down
Large multiplayer servers add human positioning play
Medal of Honor: Allied Assault
historic multiplayer scene rewarded outguessing humans
Same score on variance - which means the number cannot separate them. The difference is in what each one asks of you.
Delta Force: Black Hawk Down
Spawning enemy placements vary slightly between attempts
Medal of Honor: Allied Assault
scripted ambushes surprise only once
Same score on optimization - which means the number cannot separate them. The difference is in what each one asks of you.
Delta Force: Black Hawk Down
Loadout choice and mission routes are learnable
Medal of Honor: Allied Assault
encounter memorization, especially Omaha Beach
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.