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
Arena fighting built on baiting substitutions and timing punishes against humans.

Execution · Competitive PvP
Reversal-timing duels where reading a human opponent's pacing decides matches.
Naruto Shippuden: Ultimate Ninja Storm 3 leans Execution (Competitive PvP); WWE 2K16 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.
Naruto Shippuden: Ultimate Ninja Storm 3
Substitution timing and combo confirms need decent hands
WWE 2K16
Reversal timing windows are the core physical test
Naruto Shippuden: Ultimate Ninja Storm 3 leans a little harder on reads, though the gap is small.
Naruto Shippuden: Ultimate Ninja Storm 3
PvP revolves around baiting substitutions from human opponents
WWE 2K16
Human opponents bait reversals and vary move timing
Same score on variance - which means the number cannot separate them. The difference is in what each one asks of you.
Naruto Shippuden: Ultimate Ninja Storm 3
Support meter and item randomness barely matter
WWE 2K16
Some grapple and AI randomness colours matches
WWE 2K16 leans a little harder on optimization, though the gap is small.
Naruto Shippuden: Ultimate Ninja Storm 3
Team composition and awakening knowledge add a thin layer
WWE 2K16
Move-set knowledge and match pacing are learnable systems
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.