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

Execution · Practiced Mastery
Corridor shooting plus picking the right squad ability for each scripted encounter.

Execution · Practiced Mastery
Linear sci-fi shooting plus spatial puzzles with fixed solutions.
Clive Barker's Jericho 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.
Clive Barker's Jericho
Aim and squad-ability timing through corridor firefights
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.
Clive Barker's Jericho
Horrors attack on fixed scripts, nothing adapts
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.
Clive Barker's Jericho
Linear set pieces with minimal randomness
Prey
Linear campaign with little randomness
Same score on optimization - which means the number cannot separate them. The difference is in what each one asks of you.
Clive Barker's Jericho
Choosing the right squad member per encounter is the layer
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.