head to head
Neither is harder. They score identically on all four axes, so the difference between them is in kind, not degree.

Optimization · Practiced Mastery
An easygoing co-op Kirby about recruiting enemies as friends and combining their elemental powers.

Optimization · Practiced Mastery
A low-pressure co-op romp that mostly tests patience for collectible completion.
Kirby Star Allies leans Optimization (Practiced Mastery); LEGO Star Wars III: The Clone Wars leans Optimization (Practiced Mastery).
Same score on execution - which means the number cannot separate them. The difference is in what each one asks of you.
Kirby Star Allies
Very low difficulty, AI allies carry fights
LEGO Star Wars III: The Clone Wars
Forgiving combat and platforming with infinite respawns
Same score on reads - which means the number cannot separate them. The difference is in what each one asks of you.
Kirby Star Allies
Friend AI helps rather than opposes
LEGO Star Wars III: The Clone Wars
Scripted droid armies never adapt to you
Same score on variance - which means the number cannot separate them. The difference is in what each one asks of you.
Kirby Star Allies
Fixed layouts and bosses
LEGO Star Wars III: The Clone Wars
Stud and brick placements are fixed once seen
Same score on optimization - which means the number cannot separate them. The difference is in what each one asks of you.
Kirby Star Allies
Friend-ability element combos solve puzzles
LEGO Star Wars III: The Clone Wars
Collectible routing and character unlocks are the only real puzzle
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.