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

Variance · Light / Casual
Tests narrative taste and choice curiosity, not competitive skill of any kind.

Variance · Light / Casual
An exploration of narrative branches that deliberately tests nothing.
The Cosmic Wheel Sisterhood leans Variance (Light / Casual); The Stanley Parable leans Variance (Light / Casual).
Same score on execution - which means the number cannot separate them. The difference is in what each one asks of you.
The Cosmic Wheel Sisterhood
Crafting cards and reading dialogue needs no dexterity
The Stanley Parable
Walking is the only input
Same score on reads - which means the number cannot separate them. The difference is in what each one asks of you.
The Cosmic Wheel Sisterhood
Characters react along scripted branches, never adapting
The Stanley Parable
The narrator is a script, however much he pretends otherwise
Same score on variance - which means the number cannot separate them. The difference is in what each one asks of you.
The Cosmic Wheel Sisterhood
Story consequences are hidden until choices land
The Stanley Parable
Endings are hidden information until you wander into them
Same score on optimization - which means the number cannot separate them. The difference is in what each one asks of you.
The Cosmic Wheel Sisterhood
Card-crafting economy is light and forgiving
The Stanley Parable
Finding all branches is a trivial checklist
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.