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

Execution · Grand Arena
A football sim where reading opponents and precise execution both decide matches.

Execution · Competitive PvP
Stick precision and constant prediction of a human opponent's tactical habits.
FIFA 20 leans Execution (Grand Arena); Pro Evolution Soccer 2015 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.
FIFA 20
precise passing, dribbling, and shot timing
Pro Evolution Soccer 2015
First touch, through-ball timing and finishing demand precise sticks
Same score on reads - which means the number cannot separate them. The difference is in what each one asks of you.
FIFA 20
reading human opponent tactics live
Pro Evolution Soccer 2015
Human opponents bait, switch tactics and punish habits
Same score on variance - which means the number cannot separate them. The difference is in what each one asks of you.
FIFA 20
minor ball physics and injury randomness
Pro Evolution Soccer 2015
Deflections and referee calls add bounded chaos
FIFA 20 leans a little harder on optimization, though the gap is small.
FIFA 20
formations and player builds solvable
Pro Evolution Soccer 2015
Formations, player roles and set pieces 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.