head to head
Neither is simply harder - they are hard in different places. Europa Universalis IV demands more reads; Fallout: New Vegas demands more execution.

Optimization · Pure Optimization
Map-painting grand strategy ruled by mana and idea optimization.

Optimization · Pure Optimization
A faction-driven RPG-shooter where build and route planning shape every ending.
Europa Universalis IV leans Optimization (Pure Optimization); Fallout: New Vegas leans Optimization (Pure Optimization).
Fallout: New Vegas leans clearly harder on execution.
Europa Universalis IV
pausable, no twitch
Fallout: New Vegas
Shooter inputs with VATS assist
Europa Universalis IV leans clearly harder on reads.
Europa Universalis IV
AI mostly scripted, some MP
Fallout: New Vegas
Scripted factions and enemies
Europa Universalis IV leans a little harder on variance, though the gap is small.
Europa Universalis IV
events, mission paths
Fallout: New Vegas
Some loot and crit RNG
Europa Universalis IV leans a little harder on optimization, though the gap is small.
Europa Universalis IV
idea groups, economy, mana spending
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.