head to head
Neither is simply harder - they are hard in different places. Fallout: New Vegas demands more execution; Fire Emblem: Radiant Dawn demands more variance.

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

Optimization · Pure Optimization
Hardest modern-era Fire Emblem, a sprawling multi-army tactics campaign where planning around hit RNG is everything.
Fallout: New Vegas leans Optimization (Pure Optimization); Fire Emblem: Radiant Dawn leans Optimization (Pure Optimization).
Fallout: New Vegas leans clearly harder on execution.
Fallout: New Vegas
Shooter inputs with VATS assist
Fire Emblem: Radiant Dawn
Grid menus; no physical skill.
Fallout: New Vegas leans a little harder on reads, though the gap is small.
Fallout: New Vegas
Scripted factions and enemies
Fire Emblem: Radiant Dawn
Enemy AI follows exploitable fixed priorities.
Fire Emblem: Radiant Dawn leans clearly harder on variance.
Fallout: New Vegas
Some loot and crit RNG
Fire Emblem: Radiant Dawn
Hit, crit, and level-up rolls threaten permadeath plans.
Fire Emblem: Radiant Dawn leans a little harder on optimization, though the gap is small.
Fallout: New Vegas
Faction routing, perks, builds heavily rewarded
Fire Emblem: Radiant Dawn
Unit deployment, BEXP routing, and map solutions dominate.
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.