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 · Competitive PvP
Stick execution and reading human opponents within a meta-driven system.

Execution · Practiced Mastery
The long-running American football simulation series.
FIFA 18 leans Execution (Competitive PvP); Madden NFL Football 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.
FIFA 18
Perfect stick skill and timing dominate dribbles and finishing
Madden NFL Football
passing, running, and tackling precision
FIFA 18 leans a little harder on reads, though the gap is small.
FIFA 18
Human opponents bait, switch tactics and counter your habits
Madden NFL Football
human opponents disguise and read plays
Same score on variance - which means the number cannot separate them. The difference is in what each one asks of you.
FIFA 18
Bounce physics and pack luck add measured chaos
Madden NFL Football
fumble and injury randomness
Madden NFL Football leans a little harder on optimization, though the gap is small.
FIFA 18
Formation, squad chemistry and meta mechanics reward study
Madden NFL Football
playbook and roster management depth
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.