head to head
Neither is simply harder - they are hard in different places. Grand Theft Auto V demands more reads; Star Fox Guard demands more optimization.

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

Optimization · Practiced Mastery
Solving camera placement puzzles, then executing the watch-and-shoot plan under time pressure.
Grand Theft Auto V leans Execution (Practiced Mastery); Star Fox Guard leans Optimization (Practiced Mastery).
Same score on execution - which means the number cannot separate them. The difference is in what each one asks of you.
Grand Theft Auto V
Driving and shooting demand decent inputs.
Star Fox Guard
Snapping between camera feeds to shoot robots needs quick hands
Grand Theft Auto V leans clearly harder on reads.
Grand Theft Auto V
Online PvP exists but mostly gear/positioning, not modeling.
Star Fox Guard
Robot waves follow fixed scripted routes, nothing adapts
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.
Star Fox Guard
Wave compositions are unknown on first attempts only
Star Fox Guard leans clearly harder on optimization.
Grand Theft Auto V
Heists, money loops, builds learnable.
Star Fox Guard
Camera placement and wave memorisation solve each map
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.