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

Execution · Competitive PvP
A crossover anime arena fighter pitting Shonen Jump heroes against each other.

Execution · Competitive PvP
Arena fighting built on baiting substitutions and timing punishes against humans.
Jump Force leans Execution (Competitive PvP); Naruto Shippuden: Ultimate Ninja Storm 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.
Jump Force
3D arena combos with generous tracking
Naruto Shippuden: Ultimate Ninja Storm 3
Substitution timing and combo confirms need decent hands
Same score on reads - which means the number cannot separate them. The difference is in what each one asks of you.
Jump Force
Human opponents force guard-break guessing
Naruto Shippuden: Ultimate Ninja Storm 3
PvP revolves around baiting substitutions from human opponents
Naruto Shippuden: Ultimate Ninja Storm 3 leans a little harder on variance, though the gap is small.
Jump Force
Full information arena duels
Naruto Shippuden: Ultimate Ninja Storm 3
Support meter and item randomness barely matter
Jump Force leans a little harder on optimization, though the gap is small.
Jump Force
Team picks and awakening meter management
Naruto Shippuden: Ultimate Ninja Storm 3
Team composition and awakening knowledge add a thin layer
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.