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
Vietnam-era large-scale multiplayer shooter mixing infantry firefights with helicopters and jungle ambushes.

Execution · Competitive PvP
Football execution with finer dribble control, human prediction, and bounce luck.
Battlefield Vietnam leans Execution (Competitive PvP); FIFA Soccer 10 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.
Battlefield Vietnam
Gunplay, vehicle handling, and helicopter piloting
FIFA Soccer 10
360-degree dribbling raised the stick-skill ceiling
Same score on reads - which means the number cannot separate them. The difference is in what each one asks of you.
Battlefield Vietnam
Human squads flank and contest objectives unpredictably
FIFA Soccer 10
Outguessing a human defender's tackle timing is constant
Same score on variance - which means the number cannot separate them. The difference is in what each one asks of you.
Battlefield Vietnam
Spawn waves and vehicle availability shuffle fights
FIFA Soccer 10
Deflections and keeper randomness swing tight matches
Same score on optimization - which means the number cannot separate them. The difference is in what each one asks of you.
Battlefield Vietnam
Map control, loadouts, and ticket-bleed knowledge
FIFA Soccer 10
Formations, tactics and manager mode 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.