head to head
Neither is simply harder - they are hard in different places. Fallout: New Vegas demands more execution; Yes, Your Grace demands more variance.

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

Optimization · Pure Optimization
A kingdom-management narrative where you ration gold and favors as a beleaguered king.
Fallout: New Vegas leans Optimization (Pure Optimization); Yes, Your Grace leans Optimization (Pure Optimization).
Fallout: New Vegas leans clearly harder on execution.
Fallout: New Vegas
Shooter inputs with VATS assist
Yes, Your Grace
Menu choices only
Fallout: New Vegas leans a little harder on reads, though the gap is small.
Fallout: New Vegas
Scripted factions and enemies
Yes, Your Grace
Petitioners are scripted, not adaptive
Yes, Your Grace leans clearly harder on variance.
Fallout: New Vegas
Some loot and crit RNG
Yes, Your Grace
Outcomes of choices hidden on first run
Fallout: New Vegas leans a little harder on optimization, though the gap is small.
Fallout: New Vegas
Faction routing, perks, builds heavily rewarded
Yes, Your Grace
Resource budgeting across known story beats is solvable
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.