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
Execution on the ball plus constant prediction of the other player's shape.

Execution · Competitive PvP
Timing-based reversals and grapple prediction inside a wrestling simulation.
Pro Evolution Soccer 2009 leans Execution (Competitive PvP); WWE 2K18 leans Execution (Competitive PvP).
Pro Evolution Soccer 2009 leans a little harder on execution, though the gap is small.
Pro Evolution Soccer 2009
Close control and finishing windows demand stick precision
WWE 2K18
Reversal timing and combo inputs decide exchanges
Pro Evolution Soccer 2009 leans a little harder on reads, though the gap is small.
Pro Evolution Soccer 2009
Online and couch opponents adjust tactics against you
WWE 2K18
Human matches turn on predicting grapple and reversal habits
Same score on variance - which means the number cannot separate them. The difference is in what each one asks of you.
Pro Evolution Soccer 2009
Ricochets and keeper parries add small randomness
WWE 2K18
Momentum and AI quirks add mild noise
Same score on optimization - which means the number cannot separate them. The difference is in what each one asks of you.
Pro Evolution Soccer 2009
Squad setup and tactical sliders reward preparation
WWE 2K18
Move-set knowledge and stamina management underpin wins
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.