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

Execution · Practiced Mastery
Wave-based co-op horde shooter.

Execution · Practiced Mastery
Co-op incursions balancing careful gunplay against randomised objectives and extraction risk.
Killing Floor 2 leans Execution (Practiced Mastery); Tom Clancy's Rainbow Six Extraction leans Execution (Practiced Mastery).
Killing Floor 2 leans a little harder on execution, though the gap is small.
Killing Floor 2
Headshot-focused aim and weapon-switching
Tom Clancy's Rainbow Six Extraction
Precise shooting and stealth movement keep squads alive
Same score on reads - which means the number cannot separate them. The difference is in what each one asks of you.
Killing Floor 2
Scripted zeds, no adaptive opponent
Tom Clancy's Rainbow Six Extraction
Alien archaeans run on scripted-random behaviour, not minds
Same score on variance - which means the number cannot separate them. The difference is in what each one asks of you.
Killing Floor 2
Spawn waves and trader loot vary
Tom Clancy's Rainbow Six Extraction
Mutating zones and randomised objectives hide each incursion's shape
Killing Floor 2 leans a little harder on optimization, though the gap is small.
Killing Floor 2
Perks, weapon synergies, money management
Tom Clancy's Rainbow Six Extraction
Operator loadouts and risk-versus-extract decisions reward system mastery
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.