head to head
Neither is meaningfully harder - they pose close to the same test. The widest gap is reads, and it is a single point.

Execution · Practiced Mastery
A free co-op top-down shooter about a marine squad purging alien-infested colonies.

Execution · Practiced Mastery
A gleefully absurd open-world crime game where the Saints conquer Steelport as celebrity gangsters.
Alien Swarm leans Execution (Practiced Mastery); Saints Row: The Third 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.
Alien Swarm
Top-down aim and friendly-fire discipline
Saints Row: The Third
Generous shooting and driving keep the skill bar moderate
Saints Row: The Third leans a little harder on reads, though the gap is small.
Alien Swarm
Swarm AI scripted by director triggers
Saints Row: The Third
Enemy syndicates never adapt to you
Alien Swarm leans a little harder on variance, though the gap is small.
Alien Swarm
Spawn timing varies modestly
Saints Row: The Third
Sandbox mayhem injects light randomness
Same score on optimization - which means the number cannot separate them. The difference is in what each one asks of you.
Alien Swarm
Class loadouts and route knowledge decide runs
Saints Row: The Third
Upgrade trees and city-takeover income are straightforwardly maximised
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.