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

Execution · Competitive PvP
Arcade wrestling testing combo execution and reversal mind-games against humans.
Naruto Shippuden: Ultimate Ninja Storm 3 leans Execution (Competitive PvP); WWE All Stars leans Execution (Competitive PvP).
WWE All Stars leans a little harder on execution, though the gap is small.
Naruto Shippuden: Ultimate Ninja Storm 3
Substitution timing and combo confirms need decent hands
WWE All Stars
Juggle combos and reversal timing drive every match
Same score on reads - which means the number cannot separate them. The difference is in what each one asks of you.
Naruto Shippuden: Ultimate Ninja Storm 3
PvP revolves around baiting substitutions from human opponents
WWE All Stars
Human opponents bait reversals in constant mind-games
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 All Stars
Slight hit randomness rarely decides outcomes
Same score on optimization - which means the number cannot separate them. The difference is in what each one asks of you.
Naruto Shippuden: Ultimate Ninja Storm 3
Team composition and awakening knowledge add a thin layer
WWE All Stars
Class matchups and move properties are quickly learnable
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.