head to head
Neither is harder. They score identically on all four axes, so the difference between them is in kind, not degree.

Optimization · Pure Optimization
A survival-crafting loop where resource budgeting matters more than combat skill.

Optimization · Pure Optimization
Side-on turn-based tactics where you manually aim ricocheting bullets for a steambot pirate crew.
Metal Gear Survive leans Optimization (Pure Optimization); SteamWorld Heist leans Optimization (Pure Optimization).
Same score on execution - which means the number cannot separate them. The difference is in what each one asks of you.
Metal Gear Survive
Spear-and-fence combat is deliberate, not twitchy
SteamWorld Heist
Manual aim and ricochet shots reward steady hands
Same score on reads - which means the number cannot separate them. The difference is in what each one asks of you.
Metal Gear Survive
Wanderers are mindless scripted zombies
SteamWorld Heist
Enemy bots follow fixed behaviors
Same score on variance - which means the number cannot separate them. The difference is in what each one asks of you.
Metal Gear Survive
Dust exploration hides resources until scouted
SteamWorld Heist
Procedural ship layouts and loot drops
Same score on optimization - which means the number cannot separate them. The difference is in what each one asks of you.
Metal Gear Survive
Base-building, crafting chains and resource budgeting carry survival
SteamWorld Heist
Crew builds, weapon picks, and turn routing carry runs
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.