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 · Pure Optimization
Piecing together a scripted murder conspiracy from hidden clues.

Optimization · Pure Optimization
Evidence-gathering and deduction-board logic with no physical or adversarial layer.
Post Mortem leans Optimization (Pure Optimization); The Testament of Sherlock Holmes 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.
Post Mortem
Point-and-click interface, zero dexterity
The Testament of Sherlock Holmes
Pointing and clicking through crime scenes
Same score on reads - which means the number cannot separate them. The difference is in what each one asks of you.
Post Mortem
Suspects follow scripted dialogue trees
The Testament of Sherlock Holmes
Suspects are written, not adapting
Same score on variance - which means the number cannot separate them. The difference is in what each one asks of you.
Post Mortem
The conspiracy is hidden information revealed by investigation
The Testament of Sherlock Holmes
Clues are hidden information until uncovered
The Testament of Sherlock Holmes leans a little harder on optimization, though the gap is small.
Post Mortem
Piecing fixed clues into the solution is the game
The Testament of Sherlock Holmes
The deduction board is a solvable logic puzzle
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.