head to head
Neither is simply harder - they are hard in different places. Craft the World demands more variance; Fallout: New Vegas demands more execution.

Optimization · Pure Optimization
Optimising a dwarf fortress economy against a randomly generated world.

Optimization · Pure Optimization
A faction-driven RPG-shooter where build and route planning shape every ending.
Craft the World leans Optimization (Pure Optimization); Fallout: New Vegas leans Optimization (Pure Optimization).
Fallout: New Vegas leans clearly harder on execution.
Craft the World
Indirect dwarf orders mean hands barely matter
Fallout: New Vegas
Shooter inputs with VATS assist
Fallout: New Vegas leans a little harder on reads, though the gap is small.
Craft the World
Monster waves follow predictable scripted triggers
Fallout: New Vegas
Scripted factions and enemies
Craft the World leans clearly harder on variance.
Craft the World
Random world generation hides resources until dug out
Fallout: New Vegas
Some loot and crit RNG
Fallout: New Vegas leans a little harder on optimization, though the gap is small.
Craft the World
Fortress layout, tech tree and crafting chains are the real game
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.