head to head
Neither is harder. They score identically on all four axes, so the difference between them is in kind, not degree.

Execution · Competitive PvP
Timing-based reversals and grapple prediction inside a wrestling simulation.

Execution · Competitive PvP
Reversal-timing duels where humans bait each other inside scripted spectacle.
WWE 2K18 leans Execution (Competitive PvP); WWE SmackDown vs. Raw 2011 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.
WWE 2K18
Reversal timing and combo inputs decide exchanges
WWE SmackDown vs. Raw 2011
Reversal timing windows reward practiced reactions
Same score on reads - which means the number cannot separate them. The difference is in what each one asks of you.
WWE 2K18
Human matches turn on predicting grapple and reversal habits
WWE SmackDown vs. Raw 2011
Versus humans, reversal baiting becomes a guessing duel
Same score on variance - which means the number cannot separate them. The difference is in what each one asks of you.
WWE 2K18
Momentum and AI quirks add mild noise
WWE SmackDown vs. Raw 2011
Momentum swings and AI quirks add mild chaos
Same score on optimization - which means the number cannot separate them. The difference is in what each one asks of you.
WWE 2K18
Move-set knowledge and stamina management underpin wins
WWE SmackDown vs. Raw 2011
Move sets, match types and creation systems are learnable
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.