head to head
Helldivers 2 asks more than Payday 2, and the gap is reads.

Optimization · Practiced Mastery
Top-tier co-op shooter against bug and bot hordes.

Execution · Practiced Mastery
Loot-driven co-op heist shooter where builds and route knowledge make perfect crimes.
Helldivers 2 leans Optimization (Practiced Mastery); Payday 2 leans Execution (Practiced Mastery).
Same score on execution - which means the number cannot separate them. The difference is in what each one asks of you.
Helldivers 2
Recoil, stratagem inputs, friendly-fire aim
Payday 2
Sustained gunfights and stealth execution under pressure
Helldivers 2 leans clearly harder on reads.
Helldivers 2
Enemies scripted, no adaptive opponent
Payday 2
Cops and guards follow spawn scripts
Helldivers 2 leans clearly harder on variance.
Helldivers 2
Patrol spawns and modifiers shake missions
Payday 2
Random vault locations, guard patrols, and escrow rolls
Helldivers 2 leans a little harder on optimization, though the gap is small.
Helldivers 2
Loadout and stratagem synergies deep
Payday 2
Skill builds and stealth route planning per heist
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.