head to head
Neither is simply harder - they are hard in different places. A Total War Saga: Troy demands more reads; Fallout: New Vegas demands more execution.

Optimization · Pure Optimization
A historical strategy game blending Bronze Age empire-building with mythic warfare.

Optimization · Pure Optimization
A faction-driven RPG-shooter where build and route planning shape every ending.
A Total War Saga: Troy leans Optimization (Pure Optimization); Fallout: New Vegas leans Optimization (Pure Optimization).
Fallout: New Vegas leans clearly harder on execution.
A Total War Saga: Troy
minimal direct manual skill, command-driven
Fallout: New Vegas
Shooter inputs with VATS assist
A Total War Saga: Troy leans clearly harder on reads.
A Total War Saga: Troy
human multiplayer opponents bluff strategies
Fallout: New Vegas
Scripted factions and enemies
Same score on variance - which means the number cannot separate them. The difference is in what each one asks of you.
A Total War Saga: Troy
minor battle randomness and morale swings
Fallout: New Vegas
Some loot and crit RNG
A Total War Saga: Troy leans a little harder on optimization, though the gap is small.
A Total War Saga: Troy
deep economy, tech, and battle-formation mastery
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.