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
Grand strategy and line-infantry battles across the Napoleonic Wars.

Optimization · Pure Optimization
Optimising road networks and production chains at a settler's pace.
Napoleon: Total War leans Optimization (Pure Optimization); The Settlers II: 10th Anniversary leans Optimization (Pure Optimization).
Napoleon: Total War leans a little harder on execution, though the gap is small.
Napoleon: Total War
Real-time battle micro under pressure
The Settlers II: 10th Anniversary
Slow road-laying needs no dexterity at all
Napoleon: Total War leans a little harder on reads, though the gap is small.
Napoleon: Total War
Multiplayer battles involve feints; campaign AI is mappable
The Settlers II: 10th Anniversary
AI opponents expand on predictable scripts
Same score on variance - which means the number cannot separate them. The difference is in what each one asks of you.
Napoleon: Total War
Morale swings and fog of war
The Settlers II: 10th Anniversary
Map resources are scripted-but-unknown until explored
Same score on optimization - which means the number cannot separate them. The difference is in what each one asks of you.
Napoleon: Total War
Campaign economy, army composition, and line tactics
The Settlers II: 10th Anniversary
Road networks and production chains are the entire game
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.