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
Chaotic tag fighter whose top tiers reward blistering execution and assist mastery.

Execution · Grand Arena
A tag-team 3D fighter layering team optimization onto Tekken's execution and reads core.
Marvel vs. Capcom 2: New Age of Heroes leans Execution (Grand Arena); Tekken Tag Tournament leans Execution (Grand Arena).
Marvel vs. Capcom 2: New Age of Heroes leans a little harder on execution, though the gap is small.
Marvel vs. Capcom 2: New Age of Heroes
infinite combos and assist timing demand elite hands
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.
Marvel vs. Capcom 2: New Age of Heroes
humans bait assists and mix high-low constantly
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.
Marvel vs. Capcom 2: New Age of Heroes
fully deterministic engine
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.
Marvel vs. Capcom 2: New Age of Heroes
team order, assist synergy, and matchup knowledge
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.