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
Classic fighting execution and human prediction atop a famously unbalanced roster.
EA Sports UFC 5 leans Execution (Competitive PvP); Mortal Kombat Trilogy 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 Trilogy
Dial-a-combo inputs and run-meter pressure demand fast hands
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 Trilogy
Human opponents must be baited into unsafe moves
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 Trilogy
Movesets are public; nothing hidden in a match
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 Trilogy
Knowing the bloated roster's broken tech is half the battle
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.