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
A sprawling military simulator where realistic ballistics and planning beat reflexes.

Execution · Practiced Mastery
A basketball sim testing shot timing and tactical play against opponents.
Arma 2 leans Execution (Competitive PvP); NBA 2K3 leans Execution (Practiced Mastery).
Same score on execution - which means the number cannot separate them. The difference is in what each one asks of you.
Arma 2
Ballistics, stance, and positioning over twitch aim
NBA 2K3
Shooting and dribble timing decide plays
Same score on reads - which means the number cannot separate them. The difference is in what each one asks of you.
Arma 2
Human squads in PvP scenarios adapt
NBA 2K3
Human opponents reward reading offense and defense
Arma 2 leans a little harder on variance, though the gap is small.
Arma 2
Vast terrain hides enemy positions
NBA 2K3
Shot success carries randomness
NBA 2K3 leans a little harder on optimization, though the gap is small.
Arma 2
Doctrine, loadouts, and mission planning
NBA 2K3
Playcalling, rotations, and team management reward planning
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.