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

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

Execution · Competitive PvP
An online multiplayer soccer game about positioning and outplaying human opponents.
Battlefield Vietnam leans Execution (Competitive PvP); Soccer Online: Ball 3D leans Execution (Competitive PvP).
Battlefield Vietnam leans a little harder on execution, though the gap is small.
Battlefield Vietnam
Gunplay, vehicle handling, and helicopter piloting
Soccer Online: Ball 3D
Controlling shots and movement precisely matters in matches
Soccer Online: Ball 3D leans a little harder on reads, though the gap is small.
Battlefield Vietnam
Human squads flank and contest objectives unpredictably
Soccer Online: Ball 3D
Outguessing human opponents' passes and positioning 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
Soccer Online: Ball 3D
Some physics unpredictability but mostly skill-driven
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
Soccer Online: Ball 3D
Team coordination and positioning tactics 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.