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 · Competitive PvP
An anime fighter testing combo execution and counter-baiting against human opponents.

Execution · Competitive PvP
Classic fighting execution and human prediction atop a famously unbalanced roster.
Dragon Ball Z: Budokai 3 leans Execution (Competitive PvP); Mortal Kombat Trilogy leans Execution (Competitive PvP).
Mortal Kombat Trilogy leans a little harder on execution, though the gap is small.
Dragon Ball Z: Budokai 3
Combo execution, teleport counters and beam timing demand hands
Mortal Kombat Trilogy
Dial-a-combo inputs and run-meter pressure demand fast hands
Same score on reads - which means the number cannot separate them. The difference is in what each one asks of you.
Dragon Ball Z: Budokai 3
Versus humans, baiting teleports and guessing cancels decides exchanges
Mortal Kombat Trilogy
Human opponents must be baited into unsafe moves
Same score on variance - which means the number cannot separate them. The difference is in what each one asks of you.
Dragon Ball Z: Budokai 3
Almost nothing random beyond minor clash inputs
Mortal Kombat Trilogy
Movesets are public; nothing hidden in a match
Mortal Kombat Trilogy leans a little harder on optimization, though the gap is small.
Dragon Ball Z: Budokai 3
Capsule builds and matchup knowledge underpin competitive play
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.