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

Execution · Competitive PvP
Striking execution and constant human mix-up prediction across MMA phases.

Execution · Competitive PvP
The toned-down crossover fighter matching Mortal Kombat's roster against DC superheroes.
EA Sports UFC 5 leans Execution (Competitive PvP); Mortal Kombat vs. DC Universe leans Execution (Competitive PvP).
Same score on execution - which means the number cannot separate them. The difference is in what each one asks of you.
EA Sports UFC 5
Strike timing, head movement and transition denial demand hands
Mortal Kombat vs. DC Universe
Juggle combos and klose kombat timing
EA Sports UFC 5 leans a little harder on reads, though the gap is small.
EA Sports UFC 5
Out-guessing a human's strike-grapple mix is the core duel
Mortal Kombat vs. DC Universe
Human mixups, though a simpler toolset than peers
EA Sports UFC 5 leans a little harder on variance, though the gap is small.
EA Sports UFC 5
Damage events and doctor stoppages add chaos
Mortal Kombat vs. DC Universe
Deterministic crossover combat
Same score on optimization - which means the number cannot separate them. The difference is in what each one asks of you.
EA Sports UFC 5
Stamina math and matchup study underpin the meta
Mortal Kombat vs. DC Universe
Mapping juggle routes and matchup tools rewards practice
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.