head to head
Super Smash Bros. for Wii U asks more than Splatoon 2, and the gap is reads.

Execution · Practiced Mastery
A team shooter where aim and positioning against human opponents controls the map.

Execution · Competitive PvP
The Wii U Smash that restored competitive pace and a huge roster of labbable kill confirms.
Splatoon 2 leans Execution (Practiced Mastery); Super Smash Bros. for Wii U 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 2
aim and movement decide ink battles
Super Smash Bros. for Wii U
Perfect pivots and precise aerial spacing reward sharp hands.
Super Smash Bros. for Wii U leans clearly harder on reads.
Splatoon 2
predicting human opponent positioning
Super Smash Bros. for Wii U
Ledge-trap and landing-trap guessing against humans never converges.
Same score on variance - which means the number cannot separate them. The difference is in what each one asks of you.
Splatoon 2
weapon and map rotation randomness
Super Smash Bros. for Wii U
Tripping removed; only minor move RNG remains.
Splatoon 2 leans a little harder on optimization, though the gap is small.
Splatoon 2
loadout and turf strategy solvable
Super Smash Bros. for Wii U
Rage mechanics and kill-confirm percents are deeply labbable.
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.