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
Handheld tactics RPG adding a shifting law system to grid battles.

Optimization · Pure Optimization
Generous team-building optimisation against fixed Kalos trainers.
Final Fantasy Tactics Advance leans Optimization (Pure Optimization); Pokémon Y leans Optimization (Pure Optimization).
Final Fantasy Tactics Advance leans a little harder on execution, though the gap is small.
Final Fantasy Tactics Advance
Turn-based grid commands only
Pokémon Y
Turn-based menus have no physical ceiling
Pokémon Y leans a little harder on reads, though the gap is small.
Final Fantasy Tactics Advance
Scripted opponents, judge rules are fixed
Pokémon Y
Campaign trainers are scripted; online play is a separate pursuit
Same score on variance - which means the number cannot separate them. The difference is in what each one asks of you.
Final Fantasy Tactics Advance
Random laws and hit rolls
Pokémon Y
Encounters and rolls add bounded, mappable randomness
Same score on optimization - which means the number cannot separate them. The difference is in what each one asks of you.
Final Fantasy Tactics Advance
Race-job ability combos reward deep planning
Pokémon Y
Mega evolutions and EV tools make optimisation the 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.