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

Execution · Competitive PvP
Outplaying a human opponent through input precision and constant tactical guessing.

Reads · Competitive PvP
The Wii entry whose slower pace and infamous random tripping pushed Smash toward defensive mind games.
FIFA 22 leans Execution (Competitive PvP); Super Smash Bros. Brawl leans Reads (Competitive PvP).
FIFA 22 leans a little harder on execution, though the gap is small.
FIFA 22
Perfect inputs win skill moves, timed finishing and defending
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.
FIFA 22
Outguessing a human's passing and defensive habits is the edge
Super Smash Bros. Brawl
Defensive bait-and-punish yomi dominates its floaty neutral.
FIFA 22 leans a little harder on variance, though the gap is small.
FIFA 22
Deflections, ref calls and pack luck inject real 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.
FIFA 22
Formations, tactics and squad building sit underneath the duel
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.