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.

Execution · Competitive PvP
Territory control through shooter execution and constant prediction of adapting human teams.

Execution · Competitive PvP
The N64 original that turned Nintendo mascots into a percent-and-knockback platform fighter.
Splatoon leans Execution (Competitive PvP); Super Smash Bros. leans Execution (Competitive PvP).
Same score on execution - which means the number cannot separate them. The difference is in what each one asks of you.
Splatoon
Aim, swim-form movement and ink management are constant demands
Super Smash Bros.
Z-cancels and DI demand fast precise inputs despite simple controls.
Super Smash Bros. leans a little harder on reads, though the gap is small.
Splatoon
Human opponents adapt flanks and pushes every match
Super Smash Bros.
Edgeguard and tech-chase guessing against adapting humans decides stocks.
Same score on variance - which means the number cannot separate them. The difference is in what each one asks of you.
Splatoon
Hidden squids in ink create momentary information gaps
Super Smash Bros.
Item spawns add randomness; tournament rules strip most of it.
Splatoon leans a little harder on optimization, though the gap is small.
Splatoon
Weapon kits, map control timing and gear builds reward study
Super Smash Bros.
Stage positioning and percent-based kill setups are learnable.
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.