head to head
Neither is meaningfully harder - they pose close to the same test. The widest gap is reads, and it is a single point.

Optimization · Pure Optimization
A faction-driven RPG-shooter where build and route planning shape every ending.

Optimization · Pure Optimization
An open-world mech JRPG whose combat rewards deep system and build optimization.
Fallout: New Vegas leans Optimization (Pure Optimization); Xenoblade Chronicles X leans Optimization (Pure Optimization).
Same score on execution - which means the number cannot separate them. The difference is in what each one asks of you.
Fallout: New Vegas
Shooter inputs with VATS assist
Xenoblade Chronicles X
positioning and arts timing in combat
Fallout: New Vegas leans a little harder on reads, though the gap is small.
Fallout: New Vegas
Scripted factions and enemies
Xenoblade Chronicles X
solo JRPG, no adapting opponent
Same score on variance - which means the number cannot separate them. The difference is in what each one asks of you.
Fallout: New Vegas
Some loot and crit RNG
Xenoblade Chronicles X
drop rates and crit rolls
Same score on optimization - which means the number cannot separate them. The difference is in what each one asks of you.
Fallout: New Vegas
Faction routing, perks, builds heavily rewarded
Xenoblade Chronicles X
deep build/skill/gear system to optimize
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.