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 · Pure Optimization
A turn-based 4X strategy game about optimizing civilization growth and tech trees over centuries.

Optimization · Pure Optimization
Deep empire optimisation over a hidden map against mappable AI.
Call to Power II leans Optimization (Pure Optimization); Sid Meier's Civilization IV leans Optimization (Pure Optimization).
Call to Power II leans a little harder on execution, though the gap is small.
Call to Power II
none, purely turn-based decisions
Sid Meier's Civilization IV
Turn-based clicks have no physical ceiling
Same score on reads - which means the number cannot separate them. The difference is in what each one asks of you.
Call to Power II
limited prediction of AI civ behavior
Sid Meier's Civilization IV
Human multiplayer adds diplomacy reads; AI is mappable
Sid Meier's Civilization IV leans a little harder on variance, though the gap is small.
Call to Power II
random events and combat outcome rolls
Sid Meier's Civilization IV
Map generation and unrevealed terrain drive early decisions
Same score on optimization - which means the number cannot separate them. The difference is in what each one asks of you.
Call to Power II
deep civilization-building and tech optimization
Sid Meier's Civilization IV
Tech paths, tile yields and expansion math dominate outcomes
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.