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
A one-on-one basketball game testing shot timing and reading the opponent.

Execution · Competitive PvP
Reversal timing and pacing against an opponent baiting your counters.
Jordan vs. Bird: One on One leans Execution (Competitive PvP); WWE 2K15 leans Execution (Competitive PvP).
Jordan vs. Bird: One on One leans a little harder on execution, though the gap is small.
Jordan vs. Bird: One on One
Timing shots, jumps and dunks needs precise input
WWE 2K15
Reversal timing windows decide most exchanges
Jordan vs. Bird: One on One leans a little harder on reads, though the gap is small.
Jordan vs. Bird: One on One
Human opponent in one-on-one can be predicted and faked
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.
Jordan vs. Bird: One on One
Shot success has mild 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.
Jordan vs. Bird: One on One
Knowing shot positions and patterns improves scoring
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.