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 · Competitive PvP
Anime fighter debuting the Drive system and famously execution-heavy cast.

Execution · Grand Arena
A hyper-fast tag fighting game defined by three-character teams and touch-of-death combos.
BlazBlue: Calamity Trigger leans Execution (Competitive PvP); Ultimate Marvel vs. Capcom 3 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.
BlazBlue: Calamity Trigger
Long anime combos and tight defensive inputs
Ultimate Marvel vs. Capcom 3
Long touch-of-death combos demand elite hands
Same score on reads - which means the number cannot separate them. The difference is in what each one asks of you.
BlazBlue: Calamity Trigger
Human opponents demand constant conditioning and adaptation
Ultimate Marvel vs. Capcom 3
Mixups and assist baits versus adapting humans
Same score on variance - which means the number cannot separate them. The difference is in what each one asks of you.
BlazBlue: Calamity Trigger
Negligible randomness in matches
Ultimate Marvel vs. Capcom 3
Almost fully deterministic
Ultimate Marvel vs. Capcom 3 leans a little harder on optimization, though the gap is small.
BlazBlue: Calamity Trigger
Frame data, drive mechanics, and matchup study
Ultimate Marvel vs. Capcom 3
Team composition and matchup knowledge run deep
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.