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

Optimization · Pure Optimization
Dungeon-crawling PS1 sequel built around DNA digivolution and grinding through randomized domains.

Optimization · Pure Optimization
A solvable type-matchup system wrapped in collection and light RNG.
Digimon World 2 leans Optimization (Pure Optimization); Pokémon Blue Version 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.
Digimon World 2
Turn-based dungeon crawling; no dexterity
Pokémon Blue Version
Menu battles have no physical component
Pokémon Blue Version leans a little harder on reads, though the gap is small.
Digimon World 2
Fixed AI encounters only
Pokémon Blue Version
Trainer AI is fixed; only link battles add fleeting prediction
Digimon World 2 leans a little harder on variance, though the gap is small.
Digimon World 2
Random dungeon layouts and recruitment rolls
Pokémon Blue Version
Encounter rolls, catch rates and crits add mapped randomness
Same score on optimization - which means the number cannot separate them. The difference is in what each one asks of you.
Digimon World 2
DNA digivolving and party math are the whole game
Pokémon Blue Version
Type chart and team building make the campaign solvable
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.