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
40k co-op horde shooter with class builds.

Execution · Practiced Mastery
Co-op melee horde shooter with deep builds.
Warhammer 40,000: Darktide leans Execution (Practiced Mastery); Warhammer: Vermintide 2 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.
Warhammer 40,000: Darktide
Melee-gunplay weaving under horde pressure
Warhammer: Vermintide 2
Melee timing, dodges, headshots demanding
Same score on reads - which means the number cannot separate them. The difference is in what each one asks of you.
Warhammer 40,000: Darktide
Scripted specials, not adaptive opponents
Warhammer: Vermintide 2
Specials are scripted, not adaptive
Same score on variance - which means the number cannot separate them. The difference is in what each one asks of you.
Warhammer 40,000: Darktide
Director spawns and weapon rolls vary
Warhammer: Vermintide 2
Director spawns and loot randomize runs
Same score on optimization - which means the number cannot separate them. The difference is in what each one asks of you.
Warhammer 40,000: Darktide
Talent trees and breakpoints heavily solved
Warhammer: Vermintide 2
Builds, talents, weapon breakpoints solvable
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.