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
Reversal timing and pacing against an opponent baiting your counters.
Pro Evolution Soccer 2009 leans Execution (Competitive PvP); WWE 2K15 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 2K15
Reversal timing windows decide most 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 2K15
Human opponents bait reversals and vary move timing
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 2K15
Chain-wrestling rock-paper-scissors minigames add randomness
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 2K15
Move sets, stamina and match pacing are learnable systems
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.