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.

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

Optimization · Practiced Mastery
Kiryu's farewell chapter protecting a baby in seaside Onomichi.
God of War Ragnarok leans Execution (Practiced Mastery); Yakuza 6: The Song of Life leans Optimization (Practiced Mastery).
God of War Ragnarok leans a little harder on execution, though the gap is small.
God of War Ragnarok
Parry timing and combo execution in combat
Yakuza 6: The Song of Life
Simplified Dragon Engine combat keeps a light timing test.
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
Yakuza 6: The Song of Life
Enemies follow fixed scripts.
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
Yakuza 6: The Song of Life
Negligible randomness.
Same score on optimization - which means the number cannot separate them. The difference is in what each one asks of you.
God of War Ragnarok
Build choices and moveset mastery solve bosses
Yakuza 6: The Song of Life
Stat feeding and heat upgrades are straightforward systems.
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.