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
Darker cinematic Zelda alternating wolf form and classic dungeon crawling.

Optimization · Pure Optimization
Planning stealth routes around fully mappable guard patterns.
The Legend of Zelda: Twilight Princess leans Optimization (Pure Optimization); Thief 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.
The Legend of Zelda: Twilight Princess
Hidden sword skills add modest combat depth
Thief
Movement timing matters but shadows forgive imprecision
Same score on reads - which means the number cannot separate them. The difference is in what each one asks of you.
The Legend of Zelda: Twilight Princess
Scripted bosses and enemies
Thief
Guards patrol fixed routes with mappable vision cones
Same score on variance - which means the number cannot separate them. The difference is in what each one asks of you.
The Legend of Zelda: Twilight Princess
First-run exploration unknowns
Thief
Patrol layouts are scripted-but-unknown on first entry
Same score on optimization - which means the number cannot separate them. The difference is in what each one asks of you.
The Legend of Zelda: Twilight Princess
Dungeon-item puzzle chains and wolf-form routing
Thief
Route planning around guard patterns is the whole game
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.