head to head
Super Smash Bros. Ultimate asks more than Lethal League, and the gap is optimization.

Execution · Competitive PvP
A PvP fighter where players smack an accelerating ball at each other until someone dies.

Reads · Competitive PvP
A platform fighter where edgeguards turn on reading the opponent.
Lethal League leans Execution (Competitive PvP); Super Smash Bros. Ultimate 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.
Lethal League
Hitting a ball at absurd speeds demands frame-tight timing
Super Smash Bros. Ultimate
Tech skill, edgeguards, and DI are mechanically heavy.
Super Smash Bros. Ultimate leans a little harder on reads, though the gap is small.
Lethal League
Human duels hinge on baiting and predicting swings
Super Smash Bros. Ultimate
Adaptive opponents drive ledge and platform mind games.
Super Smash Bros. Ultimate leans a little harder on variance, though the gap is small.
Lethal League
Ball physics are deterministic
Super Smash Bros. Ultimate
Stage hazards and items if enabled.
Super Smash Bros. Ultimate leans clearly harder on optimization.
Lethal League
Small movesets, light character knowledge layer
Super Smash Bros. Ultimate
Matchup knowledge and kill confirms are learnable.
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.