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
Classic Roman city builder dominated by mastering its walker-based logistics.

Optimization · Pure Optimization
Solving an interstellar logistics and power-engineering puzzle to construct a Dyson Sphere.
Caesar III leans Optimization (Pure Optimization); Dyson Sphere Program 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.
Caesar III
Mouse-driven building, no pressure
Dyson Sphere Program
All input is construction clicks with no combat ceiling
Same score on reads - which means the number cannot separate them. The difference is in what each one asks of you.
Caesar III
Invasions are scheduled, not adaptive
Dyson Sphere Program
No adversary exists in the default game mode
Same score on variance - which means the number cannot separate them. The difference is in what each one asks of you.
Caesar III
Minor walker pathing unpredictability
Dyson Sphere Program
Star system layouts vary per seed but are fully mappable
Dyson Sphere Program leans a little harder on optimization, though the gap is small.
Caesar III
Housing blocks and walker logistics are solvable systems
Dyson Sphere Program
Interstellar logistics and sphere construction are a pure engineering optimisation problem
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.