head to head
Neither is harder. They score identically on all four axes, so the difference between them is in kind, not degree.

Execution · Competitive PvP
Fast arena-fighter execution plus guessing games against a human opponent.

Execution · Competitive PvP
An analog-control boxing game where parry timing and feints decide versus bouts.
Dragon Ball Z: Budokai Tenkaichi 3 leans Execution (Competitive PvP); Fight Night Round 3 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.
Dragon Ball Z: Budokai Tenkaichi 3
Combo timing, dashes and beam clashes demand fast hands
Fight Night Round 3
Analog punch swings and parry timing set the skill ceiling
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 Tenkaichi 3
Versus humans, baiting counters and vanish wars is prediction
Fight Night Round 3
Versus boxing is feinting and baiting an adapting human
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 Tenkaichi 3
Almost nothing hidden once both rosters are known
Fight Night Round 3
Minor cut and stun randomness
Same score on optimization - which means the number cannot separate them. The difference is in what each one asks of you.
Dragon Ball Z: Budokai Tenkaichi 3
Character tiers and combo routes form a learnable layer
Fight Night Round 3
Stamina management and fighter builds are studyable
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.