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
Play-calling mind games against a human layered over stick execution and roster planning.

Reads · Competitive PvP
The Wii entry whose slower pace and infamous random tripping pushed Smash toward defensive mind games.
All-Pro Football 2K8 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.
All-Pro Football 2K8
Stick skills on passes, jukes and tackles decide individual plays
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.
All-Pro Football 2K8
Play-calling against a human is a genuine prediction duel
Super Smash Bros. Brawl
Defensive bait-and-punish yomi dominates its floaty neutral.
Same score on variance - which means the number cannot separate them. The difference is in what each one asks of you.
All-Pro Football 2K8
Catches, fumbles and matchup rolls add per-play noise
Super Smash Bros. Brawl
Random tripping injects genuine uncontrollable RNG into movement.
All-Pro Football 2K8 leans a little harder on optimization, though the gap is small.
All-Pro Football 2K8
Roster construction and playbook knowledge set the floor
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.