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

Execution · Practiced Mastery
An action adventure rewarding combat timing against scripted boss patterns.

Optimization · Practiced Mastery
A PSP prequel following three keyblade wielders with a deep command-melding build system.
God of War Ragnarok leans Execution (Practiced Mastery); Kingdom Hearts Birth by Sleep leans Optimization (Practiced Mastery).
Same score on execution - which means the number cannot separate them. The difference is in what each one asks of you.
God of War Ragnarok
Parry timing and combo execution in combat
Kingdom Hearts Birth by Sleep
Dodge timing against brutal secret bosses
Same score on reads - which means the number cannot separate them. The difference is in what each one asks of you.
God of War Ragnarok
Bosses use fixed movesets
Kingdom Hearts Birth by Sleep
Pattern-based bosses, no adaptation
Same score on variance - which means the number cannot separate them. The difference is in what each one asks of you.
God of War Ragnarok
Negligible randomness
Kingdom Hearts Birth by Sleep
Command melding outcomes are documented
Kingdom Hearts Birth by Sleep leans a little harder on optimization, though the gap is small.
God of War Ragnarok
Build choices and moveset mastery solve bosses
Kingdom Hearts Birth by Sleep
Command deck melding largely solves the 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.