head to head
Fallout: New Vegas asks more than Utawarerumono: Prelude to the Fallen, and the gap is execution.

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

Optimization · Pure Optimization
Solvable grid-tactics battles stitched between long visual-novel chapters.
Fallout: New Vegas leans Optimization (Pure Optimization); Utawarerumono: Prelude to the Fallen leans Optimization (Pure Optimization).
Fallout: New Vegas leans clearly harder on execution.
Fallout: New Vegas
Shooter inputs with VATS assist
Utawarerumono: Prelude to the Fallen
Timed attack prompts add only a sliver of dexterity
Fallout: New Vegas leans a little harder on reads, though the gap is small.
Fallout: New Vegas
Scripted factions and enemies
Utawarerumono: Prelude to the Fallen
Enemy AI follows fixed tactical scripts on a grid
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
Utawarerumono: Prelude to the Fallen
Mild crit randomness inside otherwise deterministic battles
Fallout: New Vegas leans a little harder on optimization, though the gap is small.
Fallout: New Vegas
Faction routing, perks, builds heavily rewarded
Utawarerumono: Prelude to the Fallen
Grid positioning, unit builds and turn order are fully 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.