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
Co-op horde shooting that tests aim plus class-build and choke-point planning.

Execution · Practiced Mastery
Zelda-meets-God-of-War action adventure starring the horseman War.
Aliens: Fireteam Elite leans Execution (Practiced Mastery); Darksiders 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.
Aliens: Fireteam Elite
Holding aim on swarming xenomorphs is the core demand
Darksiders
combo-driven combat with dodge timing
Same score on reads - which means the number cannot separate them. The difference is in what each one asks of you.
Aliens: Fireteam Elite
Horde AI rushes on scripts, never modelling the squad
Darksiders
enemies are scripted
Aliens: Fireteam Elite leans a little harder on variance, though the gap is small.
Aliens: Fireteam Elite
Spawn mixes vary mildly between runs
Darksiders
world and bosses are fixed
Darksiders leans a little harder on optimization, though the gap is small.
Aliens: Fireteam Elite
Class builds, perk synergies and choke-point setups are solvable
Darksiders
Zelda-style dungeons and upgrade routing
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.