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 · Competitive PvP
Classic licensed football testing input control and opponent pattern reading.

Execution · Competitive PvP
Punch timing and counter prediction in movie-licensed boxing.
FIFA Soccer 2005 leans Execution (Competitive PvP); Rocky Legends leans Execution (Competitive PvP).
FIFA Soccer 2005 leans a little harder on execution, though the gap is small.
FIFA Soccer 2005
Off-the-ball control and finishing timing are mechanical skill
Rocky Legends
Punch timing and blocking windows carry every exchange
Same score on reads - which means the number cannot separate them. The difference is in what each one asks of you.
FIFA Soccer 2005
Human opponents adjust attack patterns across a match
Rocky Legends
Human opponents feint and bait counters in versus
FIFA Soccer 2005 leans a little harder on variance, though the gap is small.
FIFA Soccer 2005
Bounces and keeper behaviour add minor chaos
Rocky Legends
Little randomness beyond minor damage rolls
Same score on optimization - which means the number cannot separate them. The difference is in what each one asks of you.
FIFA Soccer 2005
Formations and exploit plays of the era are learnable
Rocky Legends
Training allocation and counter knowledge are plannable
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.