head to head
Neither is simply harder - they are hard in different places. Age of Wonders 4 demands more variance; Fallout: New Vegas demands more execution.

Optimization · Pure Optimization
Stacking tome and trait combinations across procedurally generated worlds with faction-wide consequences.

Optimization · Pure Optimization
A faction-driven RPG-shooter where build and route planning shape every ending.
Age of Wonders 4 leans Optimization (Pure Optimization); Fallout: New Vegas leans Optimization (Pure Optimization).
Fallout: New Vegas leans clearly harder on execution.
Age of Wonders 4
All decisions are turn-based; nothing physical
Fallout: New Vegas
Shooter inputs with VATS assist
Age of Wonders 4 leans a little harder on reads, though the gap is small.
Age of Wonders 4
AI rulers use scripted tomes and no real player modelling
Fallout: New Vegas
Scripted factions and enemies
Age of Wonders 4 leans clearly harder on variance.
Age of Wonders 4
Procedural world generation and tome discovery add hidden layers
Fallout: New Vegas
Some loot and crit RNG
Age of Wonders 4 leans a little harder on optimization, though the gap is small.
Age of Wonders 4
Tome selection and trait stacking create a vast combinatorial optimization space
Fallout: New Vegas
Faction routing, perks, builds heavily rewarded
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.