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
Stylish JRPG where phantom thieves steal hearts on a tightly optimized school calendar.

Optimization · Pure Optimization
Exploiting the press-turn system through demon fusion and weakness math.
Persona 5 leans Optimization (Pure Optimization); Shin Megami Tensei: Nocturne 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.
Persona 5
Stylish menus, not reflexes
Shin Megami Tensei: Nocturne
Turn-based menus carry zero dexterity demands
Same score on reads - which means the number cannot separate them. The difference is in what each one asks of you.
Persona 5
Palace enemies use fixed weaknesses
Shin Megami Tensei: Nocturne
Brutal bosses still run fixed scripts
Same score on variance - which means the number cannot separate them. The difference is in what each one asks of you.
Persona 5
Fusion alerts and negotiation rolls
Shin Megami Tensei: Nocturne
Unknown boss gimmicks and fusion luck sting first attempts
Same score on optimization - which means the number cannot separate them. The difference is in what each one asks of you.
Persona 5
Confidant calendar routing and baton-pass weakness chains
Shin Megami Tensei: Nocturne
Press-turn exploitation and fusion planning decide everything
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.