head to head
Neither is simply harder - they are hard in different places. Grand Theft Auto: San Andreas demands more optimization; Wolfenstein: The New Order demands more execution.

Optimization · Practiced Mastery
A sprawling open-world crime epic with RPG-style character stats across a whole state.

Execution · Practiced Mastery
Alt-history FPS pivoting between brutal combat and quiet moments.
Grand Theft Auto: San Andreas leans Optimization (Practiced Mastery); Wolfenstein: The New Order leans Execution (Practiced Mastery).
Wolfenstein: The New Order leans clearly harder on execution.
Grand Theft Auto: San Andreas
Flying school and drive-bys need decent hands
Wolfenstein: The New Order
Dual-wield shooting and movement demand inputs.
Wolfenstein: The New Order leans a little harder on reads, though the gap is small.
Grand Theft Auto: San Andreas
Gang AI is scripted, never adaptive
Wolfenstein: The New Order
Nazi AI scripted, predictable.
Grand Theft Auto: San Andreas leans a little harder on variance, though the gap is small.
Grand Theft Auto: San Andreas
Territory wars and traffic add light randomness
Wolfenstein: The New Order
Almost no randomness.
Grand Theft Auto: San Andreas leans clearly harder on optimization.
Grand Theft Auto: San Andreas
Stats, gym, weapon skill, and routes reward systematic play
Wolfenstein: The New Order
Perks and weapon upgrades light.
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.