head to head
Call of Duty: Modern Warfare 2 asks more than WCW/nWo Thunder, and the gap is execution.

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

Execution · Competitive PvP
A wrestling game about timing grapples and, versus humans, reading reversals.
Call of Duty: Modern Warfare 2 leans Execution (Competitive PvP); WCW/nWo Thunder 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
WCW/nWo Thunder
Grapple and strike timing decide exchanges
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
WCW/nWo Thunder
Human opponents must be anticipated and countered
Call of Duty: Modern Warfare 2 leans a little harder on variance, though the gap is small.
Call of Duty: Modern Warfare 2
Spawn flips and killstreak randomness
WCW/nWo Thunder
Reversal windows add some unpredictability
Call of Duty: Modern Warfare 2 leans a little harder on optimization, though the gap is small.
Call of Duty: Modern Warfare 2
Killstreak economy, loadout and map knowledge
WCW/nWo Thunder
Move-set knowledge and stamina management matter
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.