head to head
Neither is meaningfully harder - they pose close to the same test. The widest gap is optimization, and it is a single point.

Execution · Grand Arena
A high-execution fighter where one-frame links and opponent modelling separate competitors.

Execution · Grand Arena
A tag-enhanced Tekken that multiplies execution demands and opponent reads by adding partner management to every exchange.
Street Fighter IV leans Execution (Grand Arena); Tekken Tag Tournament 2 leans Execution (Grand Arena).
Same score on execution - which means the number cannot separate them. The difference is in what each one asks of you.
Street Fighter IV
One-frame links and FADC combos demand extreme motor precision
Tekken Tag Tournament 2
Tag combos and partner launcher extensions demand high motor precision
Same score on reads - which means the number cannot separate them. The difference is in what each one asks of you.
Street Fighter IV
Reading opponent habits, wake-up patterns, and adaptations is the meta
Tekken Tag Tournament 2
Tag crash timing and incoming character reads against humans are constant
Same score on variance - which means the number cannot separate them. The difference is in what each one asks of you.
Street Fighter IV
Virtually no RNG; every outcome is skill-driven
Tekken Tag Tournament 2
No RNG; all information is visible
Tekken Tag Tournament 2 leans a little harder on optimization, though the gap is small.
Street Fighter IV
Frame data, punish windows, and matchup charts are deeply studied
Tekken Tag Tournament 2
Tag team pairings and shared health management reward deep preparation
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.