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 · Pure Mechanics
Island-themed collection of twelve motion-controlled sports showcasing the Wii MotionPlus accessory.
Grand Theft Auto V leans Execution (Practiced Mastery); Wii Sports Resort leans Execution (Pure Mechanics).
Wii Sports Resort leans a little harder on execution, though the gap is small.
Grand Theft Auto V
Driving and shooting demand decent inputs.
Wii Sports Resort
MotionPlus precision in swordplay, archery and bowling
Same score on reads - which means the number cannot separate them. The difference is in what each one asks of you.
Grand Theft Auto V
Online PvP exists but mostly gear/positioning, not modeling.
Wii Sports Resort
Local versus duels involve mild feinting
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.
Wii Sports Resort
Slight physics and CPU pattern randomness
Grand Theft Auto V leans a little harder on optimization, though the gap is small.
Grand Theft Auto V
Heists, money loops, builds learnable.
Wii Sports Resort
Each event has small learnable technique optima
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.