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

Execution · Practiced Mastery
A team arcade racer with no finish line, scoring takedowns and objectives in a rolling stampede.

Execution · Competitive PvP
Large-battle aim and positioning with light prediction against human players.
Onrush 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.
Onrush
Boost management and aerial takedowns need car control
Star Wars: Battlefront II
Aimbot dominates infantry fights and starfighter dogfights
Star Wars: Battlefront II leans a little harder on reads, though the gap is small.
Onrush
Team-based human opponents in stampede modes
Star Wars: Battlefront II
Human opponents in multiplayer create modest prediction play
Same score on variance - which means the number cannot separate them. The difference is in what each one asks of you.
Onrush
Chaotic pack collisions and fodder spawns
Star Wars: Battlefront II
Spawns, vehicle availability and hero pickups add chaos
Onrush leans a little harder on optimization, though the gap is small.
Onrush
Class roles and rush timing are learnable
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.