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
A test of precise inputs and constant human prediction across a fixed roster of matchup puzzles.

Execution · Grand Arena
A tag-team 3D fighter layering team optimization onto Tekken's execution and reads core.
Street Fighter II: The World Warrior leans Execution (Competitive PvP); Tekken Tag Tournament leans Execution (Grand Arena).
Street Fighter II: The World Warrior leans a little harder on execution, though the gap is small.
Street Fighter II: The World Warrior
Frame-precise inputs and combo timing define every matchup
Tekken Tag Tournament
Tag combos and netsu juggles demand precise inputs
Same score on reads - which means the number cannot separate them. The difference is in what each one asks of you.
Street Fighter II: The World Warrior
Predicting human opponent's next move is constant and non-convergent
Tekken Tag Tournament
Tag timing adds another layer of human mind-games
Same score on variance - which means the number cannot separate them. The difference is in what each one asks of you.
Street Fighter II: The World Warrior
No meaningful RNG; match outcomes are skill-determined
Tekken Tag Tournament
Open information; nothing hidden between rounds
Tekken Tag Tournament leans a little harder on optimization, though the gap is small.
Street Fighter II: The World Warrior
Character matchups and punish routes are learnable but not fully solvable
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.