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

Execution · Pure Mechanics
A 1977 timing test - lead the moving target and outscore the other gun.

Execution · Pure Mechanics
Routine shooter aim through scripted cartel firefights.
Air-Sea Battle leans Execution (Pure Mechanics); Call of Juarez: The Cartel leans Execution (Pure Mechanics).
Same score on execution - which means the number cannot separate them. The difference is in what each one asks of you.
Air-Sea Battle
Timing shots on moving targets is the entire game
Call of Juarez: The Cartel
Standard FPS gunfights run on aim alone
Same score on reads - which means the number cannot separate them. The difference is in what each one asks of you.
Air-Sea Battle
Head-to-head play adds slight outguessing of the other gunner
Call of Juarez: The Cartel
Co-op secret objectives add mild teammate suspicion
Same score on variance - which means the number cannot separate them. The difference is in what each one asks of you.
Air-Sea Battle
Target patterns cycle predictably
Call of Juarez: The Cartel
Enemy waves spawn identically each run
Call of Juarez: The Cartel leans a little harder on optimization, though the gap is small.
Air-Sea Battle
Learning target speeds and angles is shallow but real
Call of Juarez: The Cartel
Weapon levelling is a thin progression layer
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.