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.

Optimization · Systems & Chaos
An ARPG loot grind about chasing affix rolls to feed a damage-stack build.

Optimization · Systems & Chaos
Skill-active survivors-like with curse stacking and boss-rush escalation.
Diablo IV leans Optimization (Systems & Chaos); Soulstone Survivors leans Optimization (Systems & Chaos).
Soulstone Survivors leans a little harder on execution, though the gap is small.
Diablo IV
Clicking and dodging are light; gear carries you.
Soulstone Survivors
Active skills and dodging beyond auto-attack.
Same score on reads - which means the number cannot separate them. The difference is in what each one asks of you.
Diablo IV
Enemies and bosses are scripted; no adaptive opponent.
Soulstone Survivors
Scripted enemy waves.
Same score on variance - which means the number cannot separate them. The difference is in what each one asks of you.
Diablo IV
Loot rolls, affixes, and uniques drive every session.
Soulstone Survivors
Skill and curse drops swing builds.
Same score on optimization - which means the number cannot separate them. The difference is in what each one asks of you.
Diablo IV
Paragon, aspects, and damage buckets are solvable theorycraft.
Soulstone Survivors
Curses and build crafting 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.