head to head
Neither is meaningfully harder - they pose close to the same test. The widest gap is variance, and it is a single point.

Reads · Competitive PvP
A 3D arena fighter where extendable-arm punches curve mid-flight in PvP duels.

Reads · Competitive PvP
The Wii entry whose slower pace and infamous random tripping pushed Smash toward defensive mind games.
ARMS leans Reads (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.
ARMS
Curving punches and dodge timing
Super Smash Bros. Brawl
Slower engine lowers the ceiling but spacing still needs hands.
Same score on reads - which means the number cannot separate them. The difference is in what each one asks of you.
ARMS
Whiff-punish games against adapting humans
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.
ARMS
Minor stage and item randomness
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.
ARMS
Arm loadout counters and matchup study
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.