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 · Competitive PvP
Modern-military 64-player shooter where squads, commanders, and vehicles contest sprawling conquest maps.

Execution · Competitive PvP
Vietnam-era large-scale multiplayer shooter mixing infantry firefights with helicopters and jungle ambushes.
Battlefield 2 leans Execution (Competitive PvP); Battlefield Vietnam 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 2
Aim, jet and chopper piloting, infantry movement
Battlefield Vietnam
Gunplay, vehicle handling, and helicopter piloting
Same score on reads - which means the number cannot separate them. The difference is in what each one asks of you.
Battlefield 2
Squads and commanders out-maneuver human opposition
Battlefield Vietnam
Human squads flank and contest objectives unpredictably
Same score on variance - which means the number cannot separate them. The difference is in what each one asks of you.
Battlefield 2
Spawn timing and vehicle contention add noise
Battlefield Vietnam
Spawn waves and vehicle availability shuffle fights
Battlefield 2 leans a little harder on optimization, though the gap is small.
Battlefield 2
Flag rotation, class roles, and commander assets
Battlefield Vietnam
Map control, loadouts, and ticket-bleed knowledge
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.