head to head
Helldivers asks more than Grand Theft Auto V, and the gap is variance.

Execution · Practiced Mastery
Sandbox crime playground spanning shooting, driving, and a persistent online economy.

Optimization · Practiced Mastery
Twin-stick co-op shooter precursor.
Grand Theft Auto V leans Execution (Practiced Mastery); Helldivers leans Optimization (Practiced Mastery).
Helldivers leans a little harder on execution, though the gap is small.
Grand Theft Auto V
Driving and shooting demand decent inputs.
Helldivers
Twin-stick aim and stratagem inputs
Grand Theft Auto V leans a little harder on reads, though the gap is small.
Grand Theft Auto V
Online PvP exists but mostly gear/positioning, not modeling.
Helldivers
Scripted enemies, no real reads
Helldivers leans clearly harder on variance.
Grand Theft Auto V
Some mission and lobby randomness.
Helldivers
Random spawns and patrol pressure
Helldivers leans clearly harder on optimization.
Grand Theft Auto V
Heists, money loops, builds learnable.
Helldivers
Loadout combos and stratagem chains
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.