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.

Optimization · Pure Optimization
A charming JRPG carried by familiar evolution and party-build routing.

Optimization · Pure Optimization
Building a team and exploiting type-matchup math against scripted trainers.
Ni no Kuni: Wrath of the White Witch leans Optimization (Pure Optimization); Pokémon LeafGreen Version leans Optimization (Pure Optimization).
Ni no Kuni: Wrath of the White Witch leans a little harder on execution, though the gap is small.
Ni no Kuni: Wrath of the White Witch
Hybrid action-turn combat, low input demand
Pokémon LeafGreen Version
Menu-driven turn battles demand no physical skill
Same score on reads - which means the number cannot separate them. The difference is in what each one asks of you.
Ni no Kuni: Wrath of the White Witch
Scripted enemies
Pokémon LeafGreen Version
Trainers are scripted; link battles are a side mode
Pokémon LeafGreen Version leans a little harder on variance, though the gap is small.
Ni no Kuni: Wrath of the White Witch
Familiar catch and drop rolls
Pokémon LeafGreen Version
Wild encounters, catch rolls and crits add mappable RNG
Same score on optimization - which means the number cannot separate them. The difference is in what each one asks of you.
Ni no Kuni: Wrath of the White Witch
Familiar evolution and party routing rewarded
Pokémon LeafGreen Version
Type matchups and team building are the solvable core
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.