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 · Competitive PvP
Hardcore team shooter where one bullet kills and the HUD tells you nothing.

Execution · Pure Mechanics
Free-to-play military shooter mixing class-based PvP with co-op missions.
Insurgency leans Execution (Competitive PvP); Warface leans Execution (Pure Mechanics).
Same score on execution - which means the number cannot separate them. The difference is in what each one asks of you.
Insurgency
One-shot lethality rewards precise aim
Warface
Aimbot dominates gunfights; recoil control and flick aim decide duels.
Insurgency leans a little harder on reads, though the gap is small.
Insurgency
Human squads flank and adapt each round
Warface
Human PvP positioning and peek mind-games in versus modes.
Insurgency leans a little harder on variance, though the gap is small.
Insurgency
No killcam or HUD hides enemy positions
Warface
Spawn and enemy position uncertainty, minor.
Same score on optimization - which means the number cannot separate them. The difference is in what each one asks of you.
Insurgency
Loadout points and objective route knowledge
Warface
Loadout grind and class synergy matter but are mappable.
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.