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
The genre-defining 1993 space 4X of galactic conquest, diplomacy and ship design.

Optimization · Pure Optimization
The 2001 Civilization entry that introduced culture, strategic resources and refined empire micromanagement.
Master of Orion leans Optimization (Pure Optimization); Sid Meier's Civilization III 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.
Master of Orion
Pure turn-based menus
Sid Meier's Civilization III
No dexterity in a turn-based interface
Same score on reads - which means the number cannot separate them. The difference is in what each one asks of you.
Master of Orion
AI emperors are predictable policy machines
Sid Meier's Civilization III
AI personalities are fixed and mappable
Same score on variance - which means the number cannot separate them. The difference is in what each one asks of you.
Master of Orion
Random galaxies and tech trees vary each game
Sid Meier's Civilization III
Random maps, resources and combat rolls matter early
Same score on optimization - which means the number cannot separate them. The difference is in what each one asks of you.
Master of Orion
Tech beelines and ship design dominate outcomes
Sid Meier's Civilization III
Corruption math, worker turns and culture borders reward deep optimization
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.