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
A flashy arena fighter testing reaction timing and substitution mind-games against humans.

Reads · Competitive PvP
The Wii entry whose slower pace and infamous random tripping pushed Smash toward defensive mind games.
Naruto x Boruto: Ultimate Ninja Storm Connections leans Execution (Competitive PvP); Super Smash Bros. Brawl leans Reads (Competitive PvP).
Same score on execution - which means the number cannot separate them. The difference is in what each one asks of you.
Naruto x Boruto: Ultimate Ninja Storm Connections
Combo timing and substitution reactions decide exchanges
Super Smash Bros. Brawl
Slower engine lowers the ceiling but spacing still needs hands.
Super Smash Bros. Brawl leans a little harder on reads, though the gap is small.
Naruto x Boruto: Ultimate Ninja Storm Connections
Human opponents bait substitutions and punish habits
Super Smash Bros. Brawl
Defensive bait-and-punish yomi dominates its floaty neutral.
Super Smash Bros. Brawl leans a little harder on variance, though the gap is small.
Naruto x Boruto: Ultimate Ninja Storm Connections
Little hidden beyond occasional support-assist surprises
Super Smash Bros. Brawl
Random tripping injects genuine uncontrollable RNG into movement.
Same score on optimization - which means the number cannot separate them. The difference is in what each one asks of you.
Naruto x Boruto: Ultimate Ninja Storm Connections
Team composition and meter management reward system knowledge
Super Smash Bros. Brawl
Matchup knowledge and ledge play reward study within a campy meta.
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.
full breakdown
Naruto x Boruto: Ultimate Ninja Storm Connections →
full breakdown
Super Smash Bros. Brawl →