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
A football sim testing play execution and play-calling prediction against opponents.

Execution · Practiced Mastery
A team shooter where aim and positioning against human opponents controls the map.
Madden Football 64 leans Execution (Practiced Mastery); Splatoon 2 leans Execution (Practiced Mastery).
Splatoon 2 leans a little harder on execution, though the gap is small.
Madden Football 64
Throw and run timing decides plays in real time
Splatoon 2
aim and movement decide ink battles
Same score on reads - which means the number cannot separate them. The difference is in what each one asks of you.
Madden Football 64
Human opponents disguise plays, demanding prediction
Splatoon 2
predicting human opponent positioning
Madden Football 64 leans a little harder on variance, though the gap is small.
Madden Football 64
Catch and fumble outcomes carry simulated randomness
Splatoon 2
weapon and map rotation randomness
Same score on optimization - which means the number cannot separate them. The difference is in what each one asks of you.
Madden Football 64
Playbook, audibles and roster tactics run deep
Splatoon 2
loadout and turf strategy solvable
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.