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
A wrestling game testing reversal timing with light mind-games against humans.
Naruto Shippuden: Ultimate Ninja Storm 3 leans Execution (Competitive PvP); TNA Impact! leans Execution (Competitive PvP).
TNA Impact! 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
TNA Impact!
Reversal timing windows decide most exchanges
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
TNA Impact!
Human opponents can be baited into whiffed grapples
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
TNA Impact!
Little is hidden beyond minor AI inconsistency
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
TNA Impact!
Move-chain knowledge runs out of depth quickly
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.