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.

Optimization · Pure Optimization
Optimizing regional economics and city services to sustain growth without collapsing your budget.

Optimization · Pure Optimization
A farm-life sim solved by season routing and profit optimization.
SimCity 4 leans Optimization (Pure Optimization); Stardew Valley 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.
SimCity 4
Point-and-click placement; zero reflex requirement
Stardew Valley
Trivial timing on fishing and combat
Same score on reads - which means the number cannot separate them. The difference is in what each one asks of you.
SimCity 4
Solo sandbox with no adversarial pressure
Stardew Valley
No adaptive opponent exists
Same score on variance - which means the number cannot separate them. The difference is in what each one asks of you.
SimCity 4
Neighbor city interactions and demand curves add unpredictability
Stardew Valley
Crop luck and geode RNG matter modestly
SimCity 4 leans a little harder on optimization, though the gap is small.
SimCity 4
Budget, ordinances, and transport networks are the core puzzle
Stardew Valley
Routing seasons, profit loops, and bundles dominates
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.