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
Card-economy management and fixed puzzle solutions with light timing inputs.

Optimization · Pure Optimization
A gentle turn-based system easily solved by build and gear choices.
Paper Mario: Color Splash leans Optimization (Pure Optimization); South Park: The Stick of Truth 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.
Paper Mario: Color Splash
Timed action commands add a light input layer
South Park: The Stick of Truth
Timed attack and block prompts add light input demands
Same score on reads - which means the number cannot separate them. The difference is in what each one asks of you.
Paper Mario: Color Splash
Enemies behave on fixed scripts
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.
Paper Mario: Color Splash
Required Thing cards are unknown until discovered
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.
Paper Mario: Color Splash
Card economy, paint management and puzzle solutions are the core
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.