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
Combined-arms multiplayer shooter famous for map-altering levolution moments and 64-player conquest.

Execution · Competitive PvP
Stick execution and reading human opponents within a meta-driven system.
Battlefield 4 leans Execution (Competitive PvP); FIFA 18 leans Execution (Competitive PvP).
Same score on execution - which means the number cannot separate them. The difference is in what each one asks of you.
Battlefield 4
Gunplay, vehicle mastery, and movement under fire
FIFA 18
Perfect stick skill and timing dominate dribbles and finishing
FIFA 18 leans a little harder on reads, though the gap is small.
Battlefield 4
Human teams adapt to flanks and levolution chokes
FIFA 18
Human opponents bait, switch tactics and counter your habits
Same score on variance - which means the number cannot separate them. The difference is in what each one asks of you.
Battlefield 4
Map-altering events and spawns inject noise
FIFA 18
Bounce physics and pack luck add measured chaos
Same score on optimization - which means the number cannot separate them. The difference is in what each one asks of you.
Battlefield 4
Loadout tuning and objective rotation knowledge
FIFA 18
Formation, squad chemistry and meta mechanics reward 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.