head to head
Neither is meaningfully harder - they pose close to the same test. The widest gap is reads, and it is a single point.

Execution · Practiced Mastery
The fastest mainline Souls, distilling the formula into aggressive boss duels.

Execution · Practiced Mastery
A serious F1 simulation testing precise car control and setup optimization.
Dark Souls III leans Execution (Practiced Mastery); Grand Prix 4 leans Execution (Practiced Mastery).
Same score on execution - which means the number cannot separate them. The difference is in what each one asks of you.
Dark Souls III
fast roll timing against aggressive scripted bosses
Grand Prix 4
Precise braking, throttle and racing-line control define lap times
Grand Prix 4 leans a little harder on reads, though the gap is small.
Dark Souls III
PvP invasions exist but are optional
Grand Prix 4
AI drivers follow scripted lines, not adapting to you
Grand Prix 4 leans a little harder on variance, though the gap is small.
Dark Souls III
fixed encounters converge after first sight
Grand Prix 4
Weather and grip add some unpredictability per race
Same score on optimization - which means the number cannot separate them. The difference is in what each one asks of you.
Dark Souls III
movesets and builds are fully mappable
Grand Prix 4
Setup tuning and optimal lines are a deep solvable layer
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.