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 · Practiced Mastery
Stick execution and opponent prediction over a franchise-management layer.

Execution · Competitive PvP
Large-battle aim and positioning with light prediction against human players.
NHL 2K6 leans Execution (Practiced Mastery); Star Wars: Battlefront II 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.
NHL 2K6
Shot timing, dekes and poke checks decide possessions
Star Wars: Battlefront II
Aimbot dominates infantry fights and starfighter dogfights
Same score on reads - which means the number cannot separate them. The difference is in what each one asks of you.
NHL 2K6
Human opponents disguise plays and bait pulls online
Star Wars: Battlefront II
Human opponents in multiplayer create modest prediction play
Star Wars: Battlefront II leans a little harder on variance, though the gap is small.
NHL 2K6
Rebounds and deflections add per-game noise
Star Wars: Battlefront II
Spawns, vehicle availability and hero pickups add chaos
NHL 2K6 leans a little harder on optimization, though the gap is small.
NHL 2K6
Line management and franchise decisions reward planning
Star Wars: Battlefront II
Class choice and map control reward learned plans
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.