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
Shot-timing execution and play-calling prediction against human or scripted defenses.

Execution · Competitive PvP
Shot timing and play selection against opponents adjusting to your tendencies.
NBA 2K12 leans Execution (Competitive PvP); NBA 2K14 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.
NBA 2K12
Shot timing and stick handles decide possessions
NBA 2K14
Shot release timing and dribble chains gate scoring
Same score on reads - which means the number cannot separate them. The difference is in what each one asks of you.
NBA 2K12
Online opponents bait defenses and adapt play calls
NBA 2K14
Online opponents counter your favourite plays
Same score on variance - which means the number cannot separate them. The difference is in what each one asks of you.
NBA 2K12
Shot RNG adds bounded noise to outcomes
NBA 2K14
Shot RNG sways close possessions
Same score on optimization - which means the number cannot separate them. The difference is in what each one asks of you.
NBA 2K12
Play calling, rosters and matchup exploits are studied systems
NBA 2K14
Playbook knowledge and roster management reward study
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.