head to head
Neither is simply harder - they are hard in different places. Portal 2 demands more optimization; Tales of Zestiria demands more variance.

Optimization · Pure Optimization
A first-person puzzle game where seeing the solution is the whole skill.

Optimization · Pure Optimization
A fantasy JRPG whose infamous equipment fusion system dominates its skill test.
Portal 2 leans Optimization (Pure Optimization); Tales of Zestiria leans Optimization (Pure Optimization).
Tales of Zestiria leans a little harder on execution, though the gap is small.
Portal 2
Portal placement requires some precision but timing is lenient.
Tales of Zestiria
Armatization combat needs timing but forgives sloppiness
Same score on reads - which means the number cannot separate them. The difference is in what each one asks of you.
Portal 2
No opponent; puzzles are static.
Tales of Zestiria
Scripted hellion AI never adapts
Tales of Zestiria leans clearly harder on variance.
Portal 2
Puzzles are deterministic with no randomness.
Tales of Zestiria
Equipment skill randomness obscures ideal gear briefly
Portal 2 leans clearly harder on optimization.
Portal 2
Solving the puzzle's logic IS the entire game.
Tales of Zestiria
Skill-fusion equipment stacking is a notorious optimization rabbit hole
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.