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 · Practiced Mastery
Sandbox crime playground spanning shooting, driving, and a persistent online economy.

Execution · Practiced Mastery
Timing-based grapple execution with light opponent prediction in multiplayer matches.
Grand Theft Auto V leans Execution (Practiced Mastery); WCW Mayhem leans Execution (Practiced Mastery).
WCW Mayhem leans a little harder on execution, though the gap is small.
Grand Theft Auto V
Driving and shooting demand decent inputs.
WCW Mayhem
Timing grapples, reversals and strikes decides every match
WCW Mayhem leans a little harder on reads, though the gap is small.
Grand Theft Auto V
Online PvP exists but mostly gear/positioning, not modeling.
WCW Mayhem
Human opponents in versus add a modest prediction layer
Same score on variance - which means the number cannot separate them. The difference is in what each one asks of you.
Grand Theft Auto V
Some mission and lobby randomness.
WCW Mayhem
Weapon spawns and AI behaviour add minor noise
Same score on optimization - which means the number cannot separate them. The difference is in what each one asks of you.
Grand Theft Auto V
Heists, money loops, builds learnable.
WCW Mayhem
Learning move lists and match-type quirks is a fixed problem
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.