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
A crossover anime arena fighter pitting Shonen Jump heroes against each other.

Reads · Competitive PvP
Anime arena fighter where managing the substitution gauge is the real duel.
Jump Force leans Execution (Competitive PvP); Naruto Shippuden: Ultimate Ninja Storm 4 leans Reads (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 4
Simple inputs; movement and substitution timing matter
Naruto Shippuden: Ultimate Ninja Storm 4 leans a little harder on reads, though the gap is small.
Jump Force
Human opponents force guard-break guessing
Naruto Shippuden: Ultimate Ninja Storm 4
Versus humans, baiting substitutions is the core game
Naruto Shippuden: Ultimate Ninja Storm 4 leans a little harder on variance, though the gap is small.
Jump Force
Full information arena duels
Naruto Shippuden: Ultimate Ninja Storm 4
Minor support-assist chaos
Same score on optimization - which means the number cannot separate them. The difference is in what each one asks of you.
Jump Force
Team picks and awakening meter management
Naruto Shippuden: Ultimate Ninja Storm 4
Team composition and matchup knowledge
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.