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

Optimization · Pure Optimization
The expanded sequel sending the SMERSH operative on more elaborate WWII infiltration missions.

Optimization · Pure Optimization
Pure stealth game about reading light and sound to ghost through guarded mansions unseen.
Death to Spies: Moment of Truth leans Optimization (Pure Optimization); Thief: Deadly Shadows leans Optimization (Pure Optimization).
Same score on execution - which means the number cannot separate them. The difference is in what each one asks of you.
Death to Spies: Moment of Truth
Stealth inputs are forgiving once the plan exists
Thief: Deadly Shadows
Quiet movement and timing windows need care, not twitch
Same score on reads - which means the number cannot separate them. The difference is in what each one asks of you.
Death to Spies: Moment of Truth
Guards never learn from your previous attempts
Thief: Deadly Shadows
Guards follow scripted patrols and alert states
Same score on variance - which means the number cannot separate them. The difference is in what each one asks of you.
Death to Spies: Moment of Truth
Initial uncertainty about patrols and objective placement
Thief: Deadly Shadows
Unknown layouts hide loot until first playthrough
Same score on optimization - which means the number cannot separate them. The difference is in what each one asks of you.
Death to Spies: Moment of Truth
Perfect routes through clockwork levels are fully solvable
Thief: Deadly Shadows
Light, sound, and route mastery makes ghosting 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.