head to head
Call of Duty: Modern Warfare 2 asks more than Naruto: Ultimate Ninja 3, and the gap is execution.

Execution · Competitive PvP
Blockbuster 2009 sequel famous for killstreak chains and frantic multiplayer.

Execution · Competitive PvP
Fast anime fights where combo execution and reading a human rival decide rounds.
Call of Duty: Modern Warfare 2 leans Execution (Competitive PvP); Naruto: Ultimate Ninja 3 leans Execution (Competitive PvP).
Call of Duty: Modern Warfare 2 leans clearly harder on execution.
Call of Duty: Modern Warfare 2
Fast time-to-kill rewards raw aim and reflex
Naruto: Ultimate Ninja 3
Combo timing and jutsu clashes reward quick hands
Call of Duty: Modern Warfare 2 leans a little harder on reads, though the gap is small.
Call of Duty: Modern Warfare 2
Outguessing human rotations and flanks
Naruto: Ultimate Ninja 3
Human versus play rewards baiting and habit punishing
Call of Duty: Modern Warfare 2 leans clearly harder on variance.
Call of Duty: Modern Warfare 2
Spawn flips and killstreak randomness
Naruto: Ultimate Ninja 3
Fights are deterministic outside clash minigames
Call of Duty: Modern Warfare 2 leans clearly harder on optimization.
Call of Duty: Modern Warfare 2
Killstreak economy, loadout and map knowledge
Naruto: Ultimate Ninja 3
Character matchups and meter use are a thin learnable layer
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.