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.

Reads · Competitive PvP
The Wii entry whose slower pace and infamous random tripping pushed Smash toward defensive mind games.

Execution · Competitive PvP
An anime fighting game testing execution and prediction against human opponents.
Super Smash Bros. Brawl leans Reads (Competitive PvP); Yu Yu Hakusho: Ghost Files - Dark Tournament 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.
Super Smash Bros. Brawl
Slower engine lowers the ceiling but spacing still needs hands.
Yu Yu Hakusho: Ghost Files - Dark Tournament
Combo timing and spacing matter in fast 2D fights
Super Smash Bros. Brawl leans a little harder on reads, though the gap is small.
Super Smash Bros. Brawl
Defensive bait-and-punish yomi dominates its floaty neutral.
Yu Yu Hakusho: Ghost Files - Dark Tournament
Human versus opponents drives prediction of attacks and blocks
Same score on variance - which means the number cannot separate them. The difference is in what each one asks of you.
Super Smash Bros. Brawl
Random tripping injects genuine uncontrollable RNG into movement.
Yu Yu Hakusho: Ghost Files - Dark Tournament
Some card-mode RNG and matchup chaos
Same score on optimization - which means the number cannot separate them. The difference is in what each one asks of you.
Super Smash Bros. Brawl
Matchup knowledge and ledge play reward study within a campy meta.
Yu Yu Hakusho: Ghost Files - Dark Tournament
Character movesets and matchups reward study
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.