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

Execution · Competitive PvP
Reversal timing and pacing against an opponent baiting your counters.

Execution · Competitive PvP
An arcade wrestling game testing grapple timing and reading opponent moves.
WWE 2K15 leans Execution (Competitive PvP); WWF: Super Wrestlemania 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 2K15
Reversal timing windows decide most exchanges
WWF: Super Wrestlemania
Grapple and move timing drive matches
Same score on reads - which means the number cannot separate them. The difference is in what each one asks of you.
WWE 2K15
Human opponents bait reversals and vary move timing
WWF: Super Wrestlemania
Human opponents allow reading grapple attempts
WWF: Super Wrestlemania leans a little harder on variance, though the gap is small.
WWE 2K15
Chain-wrestling rock-paper-scissors minigames add randomness
WWF: Super Wrestlemania
Some randomness in move success
WWE 2K15 leans a little harder on optimization, though the gap is small.
WWE 2K15
Move sets, stamina and match pacing are learnable systems
WWF: Super Wrestlemania
Move knowledge and stamina give modest edge
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.