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

Optimization · Practiced Mastery
A real-time RPG carried by ascension-grid routing and magic crafting.

Optimization · Pure Optimization
A gentle turn-based system easily solved by build and gear choices.
Final Fantasy XV leans Optimization (Practiced Mastery); South Park: The Stick of Truth leans Optimization (Pure Optimization).
Final Fantasy XV leans a little harder on execution, though the gap is small.
Final Fantasy XV
Real-time combat, modest input demand
South Park: The Stick of Truth
Timed attack and block prompts add light input demands
Final Fantasy XV leans a little harder on reads, though the gap is small.
Final Fantasy XV
Scripted enemies
South Park: The Stick of Truth
Enemies follow fixed turn-based scripts
Same score on variance - which means the number cannot separate them. The difference is in what each one asks of you.
Final Fantasy XV
Loot and ascension variance
South Park: The Stick of Truth
Minor damage rolls; encounters are otherwise fixed
Same score on optimization - which means the number cannot separate them. The difference is in what each one asks of you.
Final Fantasy XV
Ascension grid, magic crafting, party planning
South Park: The Stick of Truth
Build, gear and ability choices comfortably solve every fight
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.