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 · Practiced Mastery
Straightforward cover-shooting aim against fully scripted enemy waves.

Execution · Practiced Mastery
Linear sci-fi shooting plus spatial puzzles with fixed solutions.
Army of Two: The Devil's Cartel leans Execution (Practiced Mastery); Prey 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.
Army of Two: The Devil's Cartel
Cover shooting rewards decent aim, nothing more
Prey
Standard FPS aim with portal disorientation added
Same score on reads - which means the number cannot separate them. The difference is in what each one asks of you.
Army of Two: The Devil's Cartel
Cartel enemies follow scripted cover AI
Prey
Alien enemies follow fixed scripts
Same score on variance - which means the number cannot separate them. The difference is in what each one asks of you.
Army of Two: The Devil's Cartel
Encounters replay identically
Prey
Linear campaign with little randomness
Prey leans a little harder on optimization, though the gap is small.
Army of Two: The Devil's Cartel
Weapon customization adds light loadout math
Prey
Portal and gravity puzzles have fixed solutions
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.