head to head
Super Smash Bros. Melee asks more than Tekken Tag Tournament, and the gap is execution.

Execution · Competitive PvP
A platform fighter with one of the highest execution ceilings in any competitive game, layered on top of deep human reads.

Execution · Grand Arena
A tag-team 3D fighter layering team optimization onto Tekken's execution and reads core.
Super Smash Bros. Melee leans Execution (Competitive PvP); Tekken Tag Tournament leans Execution (Grand Arena).
Super Smash Bros. Melee leans clearly harder on execution.
Super Smash Bros. Melee
Wavedashing, L-cancels, and tech-chasing set an extreme physical ceiling
Tekken Tag Tournament
Tag combos and netsu juggles demand precise inputs
Super Smash Bros. Melee leans a little harder on reads, though the gap is small.
Super Smash Bros. Melee
Reading DI choices and opponent adaptive habits is constant and non-convergent
Tekken Tag Tournament
Tag timing adds another layer of human mind-games
Super Smash Bros. Melee leans a little harder on variance, though the gap is small.
Super Smash Bros. Melee
Stage hazard RNG and spawn positions add marginal chaos
Tekken Tag Tournament
Open information; nothing hidden between rounds
Same score on optimization - which means the number cannot separate them. The difference is in what each one asks of you.
Super Smash Bros. Melee
Character matchup tiers and optimal movement routing are deeply studied
Tekken Tag Tournament
Team synergy and tag combo routing are optimizable systems
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.