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 · Pure Mechanics
The N64 entry whose boost-or-survive health gamble layers routing decisions onto raw speed control.

Execution · Practiced Mastery
Open-world driving that tests car control with a tuning layer underneath.
F-Zero X leans Execution (Pure Mechanics); Forza Horizon leans Execution (Practiced Mastery).
F-Zero X leans a little harder on execution, though the gap is small.
F-Zero X
Sixty-frame control of thirty machines at top speed
Forza Horizon
Driving skill with assists off carries every event
Same score on reads - which means the number cannot separate them. The difference is in what each one asks of you.
F-Zero X
Rival AI is non-adaptive
Forza Horizon
AI drivatars follow patterns; casual online adds little
Same score on variance - which means the number cannot separate them. The difference is in what each one asks of you.
F-Zero X
X Cup random tracks are a minor mode
Forza Horizon
The open world is fixed and fully discoverable
Same score on optimization - which means the number cannot separate them. The difference is in what each one asks of you.
F-Zero X
Boost-health tradeoffs and shortcuts reward routing
Forza Horizon
Car tuning and racing lines reward systematic study
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.