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 · Grand Arena
A tag-team 3D fighter layering team optimization onto Tekken's execution and reads core.

Execution · Grand Arena
Frame-perfect execution fused with constant prediction of an adapting human opponent.
Tekken Tag Tournament leans Execution (Grand Arena); Ultra Street Fighter IV leans Execution (Grand Arena).
Ultra Street Fighter IV leans a little harder on execution, though the gap is small.
Tekken Tag Tournament
Tag combos and netsu juggles demand precise inputs
Ultra Street Fighter IV
One-frame links and FADC timing set a brutal hands ceiling
Same score on reads - which means the number cannot separate them. The difference is in what each one asks of you.
Tekken Tag Tournament
Tag timing adds another layer of human mind-games
Ultra Street Fighter IV
Footsies and conditioning the human opponent is the core duel
Same score on variance - which means the number cannot separate them. The difference is in what each one asks of you.
Tekken Tag Tournament
Open information; nothing hidden between rounds
Ultra Street Fighter IV
Almost nothing hidden once both characters are known
Same score on optimization - which means the number cannot separate them. The difference is in what each one asks of you.
Tekken Tag Tournament
Team synergy and tag combo routing are optimizable systems
Ultra Street Fighter IV
Frame data, matchups and option-selects form deep studied theory
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.