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

Execution · Competitive PvP
Team-based WWII infantry shooter about holding and capturing map points.

Execution · Competitive PvP
An acrobatic online shooter about movement-heavy gunplay against humans.
Day of Defeat: Source leans Execution (Competitive PvP); GunZ 2: The Second Duel leans Execution (Competitive PvP).
Same score on execution - which means the number cannot separate them. The difference is in what each one asks of you.
Day of Defeat: Source
Recoil control and snap aim decide most firefights
GunZ 2: The Second Duel
Acrobatic movement and aim are the core skill ceiling
Same score on reads - which means the number cannot separate them. The difference is in what each one asks of you.
Day of Defeat: Source
Human squads shift pushes and holds unpredictably
GunZ 2: The Second Duel
Against humans, predicting movement and fakes matters
Same score on variance - which means the number cannot separate them. The difference is in what each one asks of you.
Day of Defeat: Source
Known maps, minimal randomness beyond spawn waves
GunZ 2: The Second Duel
Minor weapon spread, mostly deterministic
Same score on optimization - which means the number cannot separate them. The difference is in what each one asks of you.
Day of Defeat: Source
Class loadouts and lane control are quickly mapped
GunZ 2: The Second Duel
Class and loadout choices support but skill leads
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.