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

Optimization · Systems & Chaos
A noir detective adventure starring Discworld's first private investigator on a case that turns lycanthropic.

Optimization · Pure Optimization
A vault management sim about optimising dwellers, rooms, and resource loops.
Discworld Noir leans Optimization (Systems & Chaos); Fallout Shelter 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.
Discworld Noir
Click-based sleuthing; nothing physical.
Fallout Shelter
Tapping menus only
Same score on reads - which means the number cannot separate them. The difference is in what each one asks of you.
Discworld Noir
Suspects recite fixed noir scripts.
Fallout Shelter
No opponent
Same score on variance - which means the number cannot separate them. The difference is in what each one asks of you.
Discworld Noir
Clue-notebook mystery hides connections until found.
Fallout Shelter
Incident spawns and lunchbox loot rolls
Fallout Shelter leans a little harder on optimization, though the gap is small.
Discworld Noir
Cross-referencing clues converges to one fixed solution.
Fallout Shelter
Dweller stats and room layout are fully 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.