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
On-the-ball flair and one-on-one deception in small-sided street matches.

Execution · Competitive PvP
Substitution baiting against humans atop simple anime-fighter inputs and team picks.
FIFA Street leans Execution (Competitive PvP); Naruto Shippuden: Ultimate Ninja Storm 2 leans Execution (Competitive PvP).
FIFA Street leans a little harder on execution, though the gap is small.
FIFA Street
Flair moves and trick timing decide 4-on-4 duels
Naruto Shippuden: Ultimate Ninja Storm 2
Timing substitutions and combos matters but inputs are simple
Same score on reads - which means the number cannot separate them. The difference is in what each one asks of you.
FIFA Street
Beating a human marker is feint-versus-anticipation
Naruto Shippuden: Ultimate Ninja Storm 2
Versus humans, baiting substitutions is the real layer
Same score on variance - which means the number cannot separate them. The difference is in what each one asks of you.
FIFA Street
Compact courts keep outcomes deterministic
Naruto Shippuden: Ultimate Ninja Storm 2
Nothing hidden once both characters are known
Naruto Shippuden: Ultimate Ninja Storm 2 leans a little harder on optimization, though the gap is small.
FIFA Street
Reputation grind and team building are light systems
Naruto Shippuden: Ultimate Ninja Storm 2
Team composition and chakra management have solvable lines
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.